Whether he thought they were his buddies is a red herring. We can run this down pretty easily. Either he thought this was a social visit with trustworthy friends or he didn’t. In the former case, the only possible reason for Flynn to lie is because the truth is SO bad that he’s afraid to tell even his trusted friends…IOW, Flynn is guilty as shit. In the latter case, Flynn lied to avoid being caught.
Either way, there’s no difference in the underlying reality and…thanks to our “law and order” friends at the GOP, police may use deception, while suspects may not. It’s their petard. About time one of them was hoisted by it.