I don't think the ATF gives a rats' behind about whether or not this gun has rust on it or if the buyer was happy or not as long as all rules were followed during transfer. That's nothing more than blowing smoke unless he plans to file false charges of some sort.

I hope the two of you can work it out.

Personally, I'd never buy a gun without a more in depth description and a few pictures.
And I agree, I think there's a pattern.