The goal of obtaining surveillance in tort cases is usually to check on the legitimacy of a claim, or ‘assess, process or settle’ it. Courts from various jurisdictions have held that it is usually carried out in preparation for litigation and is thus privileged: Murray v. Woodstock General Hospital Trust (1988), 66 OR (2d) 129 (ONDC); Davis v. Toronto Transit Commission, 2018 ONSC 7527. However, production is required where the privilege is waived: Thorpe v. Insurance Corp. of British Columbia, 2001 BCSC 1086; Lanthier v. Volk, 2006 BCSC 2092; Huntley v. Larkin, 2007 NSSC 298; O’Scolai v. Antrajenda, 2008 ABQB 77; Chong v. Lee, 2014 BCSC 734;
In certain cases, the defendant may try to use the surveillance to challenge the credibility of a plaintiff. Of course, that is most crucial when the claim rests predominantly on the testimony of the victim. The first rule to follow is the disclosure of the information pursuant to Rule 31.02 of the New Brunswick Rules of Court, even if privileged: Imperial Oil v. Jacques, 2014 SCC 66; Iannarella v. Corbett, 2015 ONCA 110 paras 40-70; Karpowicz v. Glessing, 2018 BCSC 887 paras 29-38; Cavouras v. Moscrop, 2019 BCSC 1762; Syed v. Petrie, 2020 ONSC 664. If a privilege is claimed and not waived, then surveillance will not be allowed in evidence, except to contradict or impeach a witness or only with leave of the court: Rule 31.09; Clark v. O’Brien (1995), 146 NSR (2d) 135 (NSCA); Landolfi v. Fargione (2006), 79 OR (3d) 767 paras 38-66(ONCA); Iannarella, supra 77-107; Brundige v. Bolton, 2017 BCSC 2664; Wray v. Pereira, 2018 ONSC 4623. Where no privilege is claimed or it is waived in time, the surveillance can be introduced as any other piece of evidence.
In order to be admissible into evidence, there are three criteria that surveillance products generally have to satisfy. They were formulated as follows in the case of R. v. Creemer,  1 CCC 14 p. 22 (NSCA):
All the cases dealing with the admissibility of photographs go to show that such admissibility depends on (1) their accuracy in truly representing the facts; (2) their fairness and absence of any intention to mislead; (3) their verification on oath by a person capable to do so.
Those criteria have been extended to video surveillance: Iannarella, supra para 94; Taylor v. Durkee, 2017 ONSC 7358 para 8. They apply whether the evidence is used to impeach the witness or on its own: Nemchin v. Green, 2019 ONCA 634 paras 10-12.
Surveillance evidence will not be admissible where it has no probative value. One example may be where a plaintiff claims for posttraumatic stress disorder with no apparent physical limitation but the video purports to show an ability to perform daily activities: Nemchin v. Green, 2017 ONSC 1321. It is instructive to note that, although the Ontario Court of Appeal held that the trial judge erred by excluding the video surveillance, “it was not so significant that the evidence would have affected the jury’s verdict on damages” (para 77). In another case, Lis v. Lombard Insurance Co., 2006 CanLII 21595 para 21 (ONSC), the trial judge held that “the surveillance videotape is not admissible because it is not relevant to the credibility of the witness Mrs. Lis as to whether or not she suffers chronic pain as a result of the accident”.
In New Brunswick, although there are no published court decisions dealing with the admissibility of surveillance in cases of motor vehicle accidents, such evidence has been used regularly: see Stephens v. Aviation Products Co. Ltd (1981), 34 NBR (2d) 694 (QB); Chiasson v. Thériault, 2018 NBQB 177; Matthews v. McIntyre, 2019 NBQB 127.