Regardless of exactly how the Coinbase transaction was initiated and cancelled, the OP's issue is with US regulation, not Coinbase's business practices.
Money services businesses have to obey aggressive KYC and AML processes or face the possibility of huge fines or getting shut down.
I would like to see a modicum of evidence that suggests this has anything to do with KYC/AML restrictions. I have seen none to date.
Coinbase is shady as hell. Don't use them.