Not revoked, per se, but all we need to do is revoke their diplomatic visa, and it is effectively the same thing. They can’t legally stay here without a visa, so it wouldn’t really matter if their home country wanted to preserve their immunity or not.
So, essentially expel him? That would be fine with me, but our State Department would tell us that it would most likely lead to a tit-for-tat expulsion of one (or more) of our diplomats in that country, etc.
Long ago, I worked with a woman who had diplomatic cover in Moscow for her job with the CIA. After many years of successful espionage, the Soviets finally caught on and expelled her. Our State Department knew perfectly well that she was a spy who got caught but, under the rules of the game, we promptly expelled one of the known KGB people working at Aeroflot in DC.