As a general rule... "If it sounds too good to be true, then it usually is." According to him, he knew what the cost of the license and branding free was, and yet he thought he could buy it 'legally' for much less?
He knew what he was buying, I would probably go as far as to say he didn't buy anything, but downloaded from one of the many scammer sites passing off other people's work.
He probably got sold a nulled version and didn't know it. I think if he was knowingly using a nulled version he would just admit it, or wouldn't go as far as claiming he was scammed. What are they going to do? Send the internet police after him?
You have to at least give him the benefit of the doubt.