Weird this is happening in California of all places, the most regulated state in the country when it comes to potentially hazardous materials and workplace and consumer safety?
The problem is mostly with unlicensed contractors, usually undocumented immigrants. It's very easy to start countertop installation business. Buy some tools, list yourself at thumbtack and you are ready to go. You can always find work by underbidding guys with license. These guys often don't even have bank accounts and work for cash.
Well sure. There is no regulation with 100% compliance, and some regulation that inspires non-compliance. Safety regulations in the trades are taken as a joke in general. An example I heard back in the day: How many OSHA inspectors does it take to change a lightbulb? Only one, but it takes him three days to do it.
Do the same characteristics that make it the most regulated state also make it the state most likely to notice these hazards before other states do? If so, it wouldn't be very weird.