I don't think the law is too harsh. you are reading into it too much. Willful.
That statement alone make room for plenty of excuses.
And I respectfully don't agree with you reagarding the using the words stop. The contractor realizes that he is doing wrong. The Inspector is just stating that if he continues he will file a complaint. The choice is up to the EC.
The word willfull does offer an out - but it is one that can be ignored as the saying goes - "Ignorance of the law..." However the reason I say it is harsh is that there has been very little and late out-reach on the law - infact the DAS is still linking to an obsolete version on their website to conceal the consequenses for violating it - I think purposefully so... JMSO
As for the word 'stop' in the context of inspectors and the use of what could be preceived as a threat.... (If put that way) They had better be DAMNED SURE the guy they tell to stop is not certified - or they stand to get sued.... I'm not an inspector - but I am sure the general demeaner of an inspector could get a city sued quick if some inspector decided to stop a job without grounds... i.e. he had better be really sure....
Back on topic though.... (So to speak) the OP was about 'promoting a level playing field'. i.e. educating GC's, architechs, engineers and developers about the law and requesting them to make a slight change in contract documents to require certification. IMO this is the best alternative to government regulation or the goose stepping minion of the DAS sicking the license police after poeple. Which would affect both the Uncertified person - the C-10 holder as an employer, and quite of possibly other Certified guys.
If section 16 had the following - people who did not have their guys up to snuff might think twice about bidding... IMO
"Licensed C-10 Electrical Contractor required to perform all work. Additionally, all Electrical Labor must comply with 3099 of the California Labor Code, and provide evidence in support of employees used."
And if Joe Blow's Electric can not provide documentation for his guys - it gives him a black eye with his client. Just as much as not having workmans comp might. Or not having a license at all - since it is an announcement that his is at risk.... IMO
The question is what do you think of that?