Now I know for a fact...or its a good possibility that this player will wind up on my card during a actual tournament.
My question is:: How do I stroke this person for this...or can I?
Maybe the best time to address this is during warm-ups while waiting for the two-minute warning. Without calling out anyone in particular, perhaps say something that everyone can understand without taking offense, like "Good morning (gents|ladies), I'm sure we're all friends, but since this is a tournament, attention to the rules is important too. Good luck!"