When Do Issues Need to Be Raised to Avoid Waiver in California Workers' Comp Cases?

In California, when are issues finalized for trial in a workers' compensation case?   Does a party to a workers' compensation proceeding waive an issue if it isn't raised at the Mandatory Settlement Conference (MSC)?   Or must an issue be raised by the start of trial to avoid waiver?    

Parties can be confronted with this problem due to the frenetic pace of workers' comp practice.  It usually comes up after MSC and before the trial date. One of the attorneys wakes up at 3 a.m. and realizes he forgot to list an issue on the Pre-Trial Conference Statement (PTCS). 

What to do?  Is it E&O time or can the issues be amended? 

Parties frequently dispute this question when one or the other raises an issue at trial not raised at MSC.  Some say all issues must be set forth on the PTCS to avoid waiver. Some take the position an issue must be identified and articulated by the start of trial to avoid waiver. 

Conflicting statutes and regulations obscure the answer.

It's my belief that the time by which an issue must be raised to avoid waiver is at trial when the parties agree to stipulations and issues on the record – in the presence of the Judge and when they are recorded by the court reporter.

The best practice is to get it right at MSC, but definitely get it right by the start of trial.

I'll be exploring these issues in an expert commentary article. Stay tuned for further details.