The President, the Senate, the Congress, Governors, Mayors, City councilmen . Hillary, The head of the IRS all have publicly admitted to violating Federal Law, and they aren't investigated. Or if they are, it is quietly dropped once the it's not in the news anymore.
And it is not a violation of federal law. No matter how much whiners want to pretend it is, an FFL holder is under NO legal requirement to complete sales to anyone. He does not have to explain his reasons to anyone either.
The appeal is to go to another gun store.
The government will only say a sale may proceed, not that it MUST proceed. They wont give gun dealers that kind of legal cover.
So DOJ will stamp their feet, but they can do nothing. And they should know they are tape recorded I bet everytime they come into that store.