Does exclusion of a witness in discovery require exclusion of the witness?

No. 16.1 did not require exclusion of his testimony, given that appellant identified no applicable court order and no evidence that the County's failure was willful. ( Mitchell v. Superior Court (2015) 243 Cal.App.4th 269, 272, 196 Cal.Rptr.3d 168 ["[E]xclusion of a party's witness for that party's failure to identify the witness in discovery is appropriate only if the omission was willful or a violation of a court order compelling a response"].)