Compelling Evidence: Collateral Witnesses

Collateral Witnesses

This article will go over the importance of collateral witnesses / lay witnesses and look at a number of decisions that will give us some important information on what to be aware of when seeking and preparing collateral testimony.

The key point of a collateral witness is to comment on their observations regarding the impact of a Plaintiff’s injuries both personally and professionally.

Having a list of collateral witnesses that can comment on behavior and functionality of the Plaintiff pre and post collision / incident is key.  Based on the evidence presented at trial, the Court will make findings of fact and collateral witnesses can play a very important role in offering some light on this process.

Collateral witnesses can include:

  1. family members, such as parents, siblings or other relatives;
  2. friends /social acquaintances;
  3. teachers / professors;
  4. students;
  5. neighbors; and
  6. co-workers.

The evidence from collateral witnesses can assist with placing weight on the theory that a Plaintiff is suffering with ongoing difficulties as a result of the sustained injuries caused by a collision or incident.

Expert opinion is typically sought after the Plaintiff has sustained the injury, In most cases, experts do not have first-hand knowledge of the Plaintiff’s challenges.  Furthermore, an injured party does not always have the self-awareness to identify all of the changes and/or challenges.

This is particularly important in cases involving head injury.  It is extremely beneficial to provide experts such as neuro-psychologists, psychiatrists and vocational consultants with the ability to speak to a witness, someone close to the injured party, who has observed the Plaintiff’s challenges and is able to provide this information.  The evidence of a family member or close friend provides the expert with context and perspective and is crucial to that expert’s findings.  Collateral witness evidence is important in all personal injury cases, whether the injuries are severe or subtle.

The importance of lay witnesses is illustrated by the case of Wallman v. John Doe, 2014 BCSC 79.  Here, the plaintiff, an emergency room physician and rental property developer, was driving his Honda Accord to the Whistler Health Care Centre when he stopped to allow for a snow plow which was blocking his path.  His vehicle was hit from behind by a Whistler Transit bus.  There is no dispute that the collision was relatively minor in terms of the physical damage sustained by the Honda and the Bus.

The plaintiff claimed to have suffered a debilitating concussion and had not returned to his pre-accident work.  The defendants contended the plaintiff was a malingerer and his failure to return to work after the Collision was a conscious plot to transform his life from a workaholic.

Over the course of the 29 day trial, the Court heard from 27 lay witnesses and 16 expert witnesses.  In addition to relying on expert opinion, plaintiff’s counsel called numerous lay witnesses including the plaintiff’s wife, friends and former co-workers;  all of whom interacted with the plaintiff both prior to and following the collision.

The Court stated that to accept the defendants’ position, it would have to completely disregard the evidence of the plaintiff, his wife, and all other lay witnesses called by the plaintiff who testified as to his sudden and dramatic change in character and personality since the Collision.  Each witness was found to be candid, credible, forthright and above all, honest.  These factors are equally important in a collateral witness.

The Court accepted that the plaintiff’s ongoing symptoms were as a result of him having suffered a MTBI (concussion) with devastating consequences and granted judgment in excess of $5,000,000.

Also take note that the credibility of the witnesses will most likely be challenged by the defence and analyzed by the Court.  See the following articles on CASE LAW CORNER on the subject of reliability and credibility of a witness.  Often times, the lay witness is credible, and therefore, the only strategy, and likely the most successful tactic, is to challenge the reliability of the said witness – and you should take the time to review these articles to learn more about these tactics that are utilized to discount a witness.

Liability Trial – Credibility and Reliability of a Witness

Credibility and Reliability of the Plaintiff’s Evidence

Collateral witnesses can be very helpful to a Court, especially as it relates to the credibility of the Plaintiff’s subjective injuries.  Compelling lay evidence from various individuals that know the Plaintiff and from witnesses that may not know the Plaintiff personally, but have had association with a Plaintiff through professional / work life and/or sporting events, or otherwise may be helpful.

As indicated, collateral witnesses can also offer helpful and compelling evidence to an expert when assessing an injured Plaintiff.  The statements from a collateral witness can assist experts with forming conclusions as to the impact of a Plaintiff’s level of impairment.  If the collateral witnesses can comment on the changes in the Plaintiff’s personality, behaviour, coping skills, difficulties in work duties and tasks, in planning, inability to prioritize or lack of organizational skills among other difficulties – this information may be very helpful to an assessor.  The identified and observed challenges may thereafter provide helpful information as the noted difficulties may be consistent with a specific type of injury which is being claimed in an action.  If these reported observations are identified to have come to light post collision, which were not present prior to the subject collision or incident, than of course this will lend weight to causation in that the accident may be deemed to have caused the onset of these reported changes in the Plaintiff.  Of course if a psychologist does not take the time to interview collateral witnesses, it is possible that the Court will not lend weight to that report.  This is a clear indication of how important collateral witnesses are to a Plaintiff’s claim and to a Court.

However, in my opinion, not much weight can be given to Dr. Sira’s opinions. As noted earlier, she did not meet Ms. Paterson or conduct any psychological testing of her or interview any collateral witnesses.  Paterson v. Hindle, 2017 BCSC 1104 (CanLII)

The evidence that is particularly helpful is when a collateral witness can comment clearly on the Plaintiff’s physical and/or mental state before and after a subject collision or incident:

There are, however, cases where the necessary findings of fact on something as subtle as a mild brain injury can be assisted by credible evidence of witnesses who can present a clear picture of a plaintiff before and after an event that is alleged to have caused the injury. Meghji v. Lee, 2011 BCSC 1108 (CanLII)

This is also highlighted in an older decision but is quite clear:

What struck me about the severity of his condition was the evidence coming from people who knew him well before the accident and then saw the significant change in his performance after the accident.  This kind of evidence is very compelling when compared to evidence from others who only examined him after the accident and had little personal knowledge of him before that time.  Warder v. Insurance Corp. of British Columbia, 1993 CanLII 724 (BCSC)

You will also need to focus on selecting collateral witnesses that can actually state that they knew the Plaintiff prior to the collision, that can say that they saw the Plaintiff more than just “intermittently” and in fact, interacted regularly with the Plaintiff, and not individuals that only came to know the Plaintiff after a subject motor vehicle collision.  This is important because if the statements and/or observations of the collateral witnesses are deemed to be credible and reliable, these facts can lend weight to arguments of causation, especially if the observed symptoms after the collision are consistent with reports the Plaintiff made to his or her expert and are deemed overall to be credible.

 It also depends on the weight given to the evidence of collateral witnesses as to the Plaintiff’s progressive decline and, in particular, witnesses who observed the Plaintiff just before and shortly after the occurrence of the accident.

 In determining whether it is probable that her current impaired situation was caused by the sequelae of the accident, or at least materially contributed to by the accident, I have considered the combined effect of the evidence of those collateral witnesses who knew the Plaintiff prior to and after her injury, the collateral witnesses who encountered the Plaintiff following the accident who were able to observe her level of function, lack of motivation, slower mental processing…”  Mastromonaco v. Moraal, 2015 BCSC 228 (CanLII)

Collateral witnesses that have clearly observed and identified the impact of the symptoms a Plaintiff suffers from can be powerful evidence:

“The collateral witnesses called by Ms. Cantin amply demonstrate the devastating impact of the pain on her ability to manage all aspects of daily living and the emotional and mental strain she experiences as a result of this constant pain. Ms. Cantin’s family doctors, and in particular, Dr. Dodds, have documented an ongoing litany of pain symptoms that have persisted since the date of the accident.” Cantin v. Petersen, 2012 BCSC 549 (CanLII) <

Seeking the witness statements early can be valuable as memories tend to fade.  Also, lay witnesses lend powerful evidence to the impact on a Plaintiff’s daily activities, their function and of course their relationships with others.  This is illustrated in Brown v. Lalani, 2005 BCSC 785 (CanLii) the testimony of the lay witnesses had a positive impact for the Plaintiff in this case:

From the testimony of the lay witnesses, it is clear that before the accident, Mr. Brown was a hard worker and a devoted family man.  At the time of the accident, he was working as a truck driver and was on his way home from work.  He also had a small business which involved the building of caskets.  He and his wife had made a plan that he would continue working in the trucking industry for as many as seven years, by which time it was hoped that the casket business would be viable and the plaintiff could leave his job as a trucker. 

The motor vehicle accident occurred only blocks from the plaintiff’s place of employment.  One of his co-workers, Mr. Clark, arrived at the scene shortly after the accident occurred.  He noticed a gash on the side of Mr. Brown’s head, but the plaintiff did not wish to go to the hospital, so he offered to drive him home.  Mr. Clark said that Mr. Brown did not seem to be “all there”.  He described him as dazed, dopey and slow.  Another individual who stopped to assist, Mr. Langlois, testified that Mr. Brown did not respond to his statement that he had first aid experience and appeared confused and disoriented.

Mr. Brown’s wife also had compelling comments:

All of the lay witnesses who know Mr. Brown described an individual who now tires easily, is unable to concentrate, can have mood swings and is subdued and quiet.   Ms. Staples described Mr. Brown as flat and emotionless.  She said that he is “just not there”.  She feels she has lost the person she loved.  Her role is sometimes more caregiver than wife as, amongst other things, she must organize the plaintiff’s days.

Also keep in mind that if relevant evidence through collateral witness is not induced an adverse inference can be drawn – be sure to select your collateral witnesses carefully and based on what is common sense:

Adverse inference may be drawn against a party for failure to submit relevant evidence which would be suspected to support the party’s case. The court may infer reasons for the evidence not being included. Prodigy Graphics Group Inc. v. Fitz-Andrews, [2000] O.J. No. 1203)

Canadian Encyclopedic Digest, CED (West. 4th), vol 26, title 61, at para. 71 (quote from Harvey J.):

“Similarly the Canadian Encyclopedic Digest, CED (West. 4th), vol 26, title 61, describes when an adverse inference should be drawn and in particular exactly (at ss. 199 – 200) what the inference is that is drawn (at ss. 199-200):

199 While the parties to a civil action have complete discretion regarding which witnesses to call, there are dangers in not advancing certain testimony. Where the plaintiff chooses not to tender important witnesses, it may result in a failure to meet the burden of proof. In a significant early decision, the Supreme Court of Canada indicated that the failure to call a witness with potentially important evidence to a party’s case was grounds for the trier of fact to presume that he evidence would have been adverse in nature …

200 More recently, the courts have qualified this approach, recognizing that an adverse inference should not arise in every case where a party failed to call a witness with evidence material to its case. Advances in disclosure and exchange of documents between parties mean that both sides now have equal access to information and can call witnesses who might assist them. Today the adverse inference is discretionary and should not be drawn unless it is warranted in all the circumstances. In particular, the judge should consider whether: there is a legitimate explanation for failing to call the witness; the witness is within the exclusive control of the party or is equally available to both parties; and the witness has key evidence to provide or is the best person to provide the evidence in question.”

We also find that expert evidence of the Plaintiff and Defence typically conflict and it is up to the Judge to make findings of fact based on the submitted evidence. Collateral statements may give weight to the medical evidence:

“There is also the fact that, for reasons I will come to, I have found the plaintiff’s evidence and that of her collateral witnesses generally credible, notwithstanding Dr. Semrau’s impressions of the plaintiff on two occasions.  I am therefore able to accord Dr. Anderson’s opinion some weight in the circumstances, despite his rather casual approach to credibility.”  Sanders v. Clarica Life Insurance Company, 2005 BCSC 88 (CanLII)

The evidence sought from a collateral witness must be analyzed carefully to determine whether it is, in fact, consistent.

I did not find the evidence of the collateral witnesses to be particularly helpful. Mr. Marten had only one experience working with Ms. Ryan after the 2008 Accident. Ms. Lucas, Ms. Arnold and Ms. Vaughan were not aware of other relevant medical conditions and previous accidents. Their accounts of Ms. Ryan’s apparent absence of symptoms in the years prior to the 2008 Accident is at odds with the reports reflected in the clinical records. Mr. Zelter stated that Ms. Ryan had been working as a waitress for many years, but that was inconsistent with her income tax returns.   Ryan v. Klakowich, 2011 BCSC 835 (CanLII)

We have also seen that a psychiatric injury was deemed to be compensable by a trial judge in Saadati v. Moorehead, 2017 SCC 28 in the absence of a medical diagnosis and on the basis of credible lay witnesses that were able to comment on the effect that the collision had on the Plaintiff’s personality post collision.  The “trial judge awarded the claimant damages for mental injury based on testimony of lay witnesses rather than on expert evidence establishing identified medical cause.”  This case emphasized that it was not the diagnosis that must be found in order for an injury to be compensable, but rather evidence of the effect of the injury on the Plaintiff was sufficient.

The trial judge found that the second accident caused S psychological injuries, including personality change and cognitive difficulties. This finding did not rest on an identified medical cause or expert evidence, but was based on the testimony of S’s friends and family to the effect that S’s personality had changed for the worse after the accident.

Some useful information as noted in ClickLaw Wikibooks:


You will need to consider whether you need anyone else to attend the trial to give evidence in support of your case. Witnesses should only be called to testify about facts that are relevant to the case and that are within the witness’ direct experience (in contrast to having heard information from another person who is not testifying).

Witnesses are generally not allowed to testify about their opinions, although there are exceptions to this general rule. One notable exception: a lay person is allowed to provide an opinion based upon personal observation of something that is commonly known (such as coming to the conclusion that it was raining outside because everyone who came inside was soaking wet). A second notable exception: an expert witness is allowed to provide an opinion based upon their specialized education, training, skills, certification or experience.

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With thanks to:  MaryAnn Reinhardt to her contribution to this article.