Legal Question in Personal Injury in California

If it occurred on the premises or while the employee was engaged in working, then more than likely the restaurant would be responsible.

This would depend upon a number of factors like the following: (1) Was the employee in the "course and scope" of their employment (e.g. working at the time of the incident); and (2) Was what they did "negligent" (i.e. did they do something unreasonable that caused you injury). You would need to provide more facts to fully analyze these issues.