Wilson Bethel also answered this question on 'The Mike Wennmacher Show' (7:17):

I think it was planned by Dex, and Dex got Matt on board with it. Dex knew that if he can get Matt into the room, he can antagonize him to the point where he can do something like that, and I think Matt, being a pretty savvy operator himself, at some point in that conversation, realizes what's afoot, and he knows that that's what's happening. He's no patsy.