
Video evidence is admissible in workers' compensation proceedings. Generally, it's obtained by a defendant after an applicant reports an injury and the defendant questions the applicant's credibility. This type of evidence can be called surveillance evidence or sub rosa evidence, and the parties often dispute when it must be produced.
The issue was addressed long ago in Downing v. City of Hayward (1988) 16 CWCR 76 (panel decision). In that case, the applicant's attorney objected to allowing his client's deposition because the defendant had failed to disclose whether or not it possessed surveillance films of him, and if it did, because it had failed to provide them to the attorney. Downing held that a defendant not only is not obligated to show any surveillance films prior to an applicant's deposition, but that it's also not obligated to disclose whether or not such films in fact exist. The WCAB explained: