This is a tough one. Impersonation of police and federal agents happens all the time. Imagine you're the cop, you get the call and youre already on high alert that guns are involved. You're gonna be extra careful. Personally, I'd have been a bit less heavy handed, but I guarantee you my wunderlic scores are higher than any police officer (if they score too high they aren't hired.) Either way, a guy claiming to be a fed shows up, alone, without a partner, to ask a guy with guns about his guns. Something is weird and any cop with any level of intelligence is going to know something is weird. Now, imagine you're the fed. Why are you alone, asking people with guns about their guns? STUPID. If ANYONE has the drop on you, you should probably comply, let alone a cop, who is clearly emotional from the word "go" while you are getting flanked by his partner. I'd say the fed was in the wrong, almost entirely. Do I care for dealing with cops jacked up on adrenaline over a simple call? Not at all, but I'm not going to fuck around, either. I'll take the handcuffs over the bullets.