Can my lawyer call witnesses that aren’t listed in the trial brief? What if new witnesses arise after the trial brief has been filed?
In a recent oral judgment, Justice Steeves discussed witness lists and whether a party is held to only those witnesses listed on its trial brief (Cambie Surgeries v British Columbia (AG) 2016 BCSC 2038). In the case at bar, the plaintiff had provided a trial brief on August 12, 2016, which listed 49 witnesses. After the trial commenced on September 6, 2016, it became apparent that the plaintiffs intended to call many more witnesses than just those listed. The plaintiffs were ordered to provide an updated witness list, and on October 19, 2016 – five weeks into trial – the plaintiffs filed a new witness list with a total of 85 witnesses.
The defendants opposed the calling of these witnesses on the basis that they were not included in the original trial brief. Justice Steeves reviewed the Supreme Court Civil Rules, which at R. 12-5(28) say that without leave of the court, a party must not lead evidence at trial from a witness unless the witness is listed in the witness list. Witness lists are described at R. 7-4 as follows:
(1) Unless the court otherwise orders, each party of record to an action must, within the time set out in the case plan order or, if none, on or before the earlier of the trial management conference and the date that is 28 days before the scheduled trial date, file and serve on every other party of record a list of the witnesses the party may call at trial, other than
(a)expert witnesses who are to provide evidence under Part 11, and
(b) adverse witnesses referred to in Rule 12-5 (20) (a) or (b).
Requirements for list
(2) Unless the court otherwise orders, a witness list must include the full name and address of each listed witness.
(3) If a party who has provided a witness list or an amended witness list later learns that the list is inaccurate or incomplete, the party must promptly
(a) amend the witness list,
(b) file the amended witness list, and
(c) serve a copy of the filed amended witness list on all parties of record.
Witness need not be called
(4) Nothing in this rule requires a party to call as a witness at trial an individual named as a witness on a witness list served by the party under subrule (1) or (3).
Justice Steeves then goes on to clarify that the combined effect of the above rules is not to prevent parties from adding witnesses after the trial brief is filed:
 Rule 12-2(3) requires that a trial brief be filed at least 28 days before trial. This is the August 5, 2016 document. As required by Form 41, it includes a list of witnesses the plaintiff intends to call. The plaintiffs now seek to add more witnesses, and they have given notice of this in the witness list filed October 19, 2016. It appears that the parties have treated the list of witnesses in the August 2016 trial brief as something akin to a R. 7-4 witness list.
 There is no dispute that a party may choose not to call a person identified as a witness in a witness list in a trial brief or otherwise. As to whether a party may add witnesses after filing a trial brief, R. 12-5(8) is clear enough that all witnesses must be named on a witness list. Rule 7-4 specifically describes the requirements of a witness list. Significantly for the subject application, R. 7-4 describes a continuing obligation to provide a summary. This must be done promptly, including any amendment, filing and service of the witness list. That is, R. 7-4 permits additions to a witness list. Further, it is logical that a R. 7 witness list can amend a witness list in a previous trial brief.
 Overall I conclude that the Rules permit the amendment of a witness list during a trial. The plaintiffs have done that here and followed the requirements under R. 7-4(3). I also note that the additional witnesses were named during the plaintiffs’ case. In this lengthy trial, scale is somewhat difficult to determine, but it can be said that it is early on in the plaintiffs’ case. Certainly there is no issue of notice with respect to the evidence of these individuals.
 I conclude that leave is not generally required to add names to a witness list. Of course, names added can be challenged on the usual basis of challenging evidence.