Ahhhh, before you start surreptitiously recording someone else, make sure you're in a one party consent state, meaning the state you live in allows you to record a private conversation if only one party consents. If you're in a two party consent state, you may be opening yourself up to other issues...
Just talk to him, tell him all the facts and that he is no longer welcome in the group, and don't engage if he tries to make a scene. Walk away.
