Yours is good advice, based on my own experience of 30 years in Canadian Public Service - I know I'm not from California, but the same principles apply. It is always easy to find a rule that allows you to say 'No' in public service, and even easier to be 'innocent' of the rules surrounding something like the SB100, with 500 approvals a year out of what, 30 million vehicles?
Given the opportunity and desire, a good public servant, or their supervisor, can turn the question around. "Here is what we would like to achieve; is there something in our rule-set that will allow us to do this?" The lab I last worked in had an administrative manager with just that attitude, and he made a lot of scientists (his internal clients) happy. Ironically, he was an ex-auditor, who used the simple test of "How can I achieve this unusual request in a manner that will withstand audit?" to arrive a many innovative solutions.
Public servants are not congenitally obstructive, and the great majority would rather send you away satisfied than angry; but, it's much easier to find a solution for a rational person than one who is foaming at the mouth!
And just like in business, it helps the client to be politely insistent, and be prepared to go up the chain-of-command when they first get to 'No' (or, 'Sorry, it can't be done.')
Ironically, I spent the first six years of my professional career with Vickers Shipbuilding Group in England. This defence contractor of 45,000 employees had bureaucratic processes that would do the California DMV proud (at least that is the impression I get from this string).