Is there any case law where a trial court improperly excluded a witness from testifying because the witness name was not disclosed during discovery?

Barrera's own authorities do not support his claim of error. For example, in Thoren v. Johnston & Washer (1972) 29 Cal.App.3d 270 the trial court excluded a witness from testifying whose name was not disclosed during discovery and mentioned only during the plaintiff's opening statement. The trial court concluded that the plaintiff's failure to disclose was an act of intentional deception, which exclusion was upheld on appeal. (Id. at pp. 274-275.)

In Deeter v. Angus (1986) 179 Cal.App.3d 241, the plaintiff sought to introduce a voice recording at trial despite having failed to produce the recording during discovery. The appellate court held the trial court properly excluded the recording because the plaintiff had purposefully concealed the tape. (Id. at p. 254 & fn. 5.)