Wouldn't it be better from a legal standpoint to power the phone off and refuse to give your pin in such cases? A no-pin cold boot is pretty hard to recover data from with GrapheneOS.

Most likely, at least you are not doing something irreversible. In all these cases, the best answer is "ask a lawyer". Before wiping a device in possession of law enforcement you definitely want to ask a lawyer.

I realize that in this case the person repeatedly asked for a lawyer, but if you are in a borderline authoritarian state, all bets are off.