I have never heard of NSF and will never shop there, as I stay out of MA when possible. With that said, it sounds like the sale took place between a different salesman than the attempted sale of the individual who was denied by the NICS. There was no suspected straw purchase at the time of sale until another employee found out, hence the sale and not a refusal.
Based on the information I have read, it does sound like something odd was going down. Personally, I don't like the laws we have, or the system we use. The charges seem to be a bunch of crap. But what also sounds like a bunch of crap is accusing NSF of stereotyping, being racist, or generally intolerant of people of Middle Eastern descent. I don't think that has anything to do with anything that went down.
The sale denial of a felon, fake ID, and asking about illegal things repeatedly likely had much more to do with it. But maybe I'm just way off base.