If it was on the free plan then all bets are off. If he was paying for a service, I believe there is enough case for a lawsuit where Google pays through their teeth for basically taking the client's data hostage.
At some point I'll move my hosted services to one or more companies, which for a cost - essential point if you want legal protection - offer me their services. And if shit happens, I get my data back. And there is someone, a physical person that I can call when shit happens and they can't hide behind AI and automated replies. Otherwise I have real leverage to sue their ass and settle for mucho dinero so they learn to behave.
Seems to me Google is not such a "service provider" company, so it's naive to let them hold your data, with zero legal protection if they decide to take it hostage.