Sure but probably not for very long, word gets round

As soon as he does something bad people will stop following him and say "yeah I don't like so-and-so anymore because of X bad thing" and then someone else will tell them, "Oh, that's not him anymore, his key got compromised, this is his new key: <whatever> -- and btw if your client supported nip-whatever it would have automatically migrated you as a follower to his new key. Use client-whatever or ask your dev to add support"