The dealer felt so "uneasy" about the sale and felt the need to tell a police officer, but he had no problem taking the guy's cash, huh?
Fact of the matter is, regardless of laws if the dealer was such a stand up guy, he would have said "no thanks" on the sale. But he didn't care the guys kept trying to "buy under the table" and their asking of how easy they could commit an NFA violation with that thing. He just took the money, then went to the cops after the fact.
Three things:
The dealer probably wasn't truly worried, if he was he would not have sold the gun.
Second, the guy passed a NICS check and was legally transporting the firearm. So what could the cop possibly do? Harass a guy who is not doing anything illegal (yet) based on racist stereotypes?
Third, the gun dealer should know better than to sell a gun to clowns asking about violating various federal laws.
Greedy son of a.....
EDITED TO ADD: Big T-shirts, stupid teeth, script writing/portrait tattoos, wearing ballcaps of teams you don't like but they match your outfit, and a high melanin count don't make someone a gangster. I see this a lot on here and no offense, a lot of you probably live in rural places and there's no such thing as a real urban gang where you live. But you really should not call people gangsters if they are not. Especially not people who are wannabes or just following a style of music they like. I could throw on a Harley T-shirt, some boots and a bandana tomorrow but would that make me a biker?
Unless someone is throwing signs, or wearing flags, or their tattoos are gang tattoos, they aren't a gangster. It's not really something you can fake, either. You wear the wrong flag in the wrong place and someone will lay you out. I've been on the bus before and seen people literally turn their sweatshirts inside out before their stop because that's not their color to wear. Only the stupidest of the stupid wear colors that aren't their own, and they sure as hell do not get gang tattoos. Most gangs will literally cut the tattoo out of you if you are caught faking it. So yeah.