In what circumstances will a plaintiff have to recover costs from a defendant in a separate motor vehicle accident?

In Gill v. Lindstrom, 2004 BCCA 632, 33 B.C.L.R. (4th) 325, the plaintiff had brought two separate actions for damages for injuries arising from two motor vehicle accidents. The defendants in both actions admitted liability before the trial commenced. The plaintiff argued that the second accident aggravated her injuries arising from the first accident. The same counsel represented both defendants. On the third day of trial, the trial judge made an order consolidating the actions. The jury found that the plaintiff was injured in the first accident but not the second. The trial judge ordered that the plaintiff recover, from the defendant in the first action, the costs she was ordered to pay to the defendant in the second action.