all i know is that if you're faking your death to avoid taxes or other legal contracts, that is illegal. i tried finding if there was a law for faking your own death in california, and i couldn't find one. i looked at some legal forums, and the best answer i got is there can be civil lawsuits for emotional distress.
i think this would be the biggest uphill battle michael would face coming back. people can be greedy, and someone will claim his "death" and resurrection has cause them emotional trauma (it will be bullshit, but michael isn't a stranger to that). the documents are clearly all fake, presenting blank spaces, blacked out spaces, and discrepancies in the autopsy versus other legal documents. in the age contract, the insurance clause doesn't even exist. no insurance company would agree to paying off if the person died of an overdose. no way.
in my opinion, there's no real proof of a death. therefore, how can you fake something that didn't exist?