That extra clause of the restricted teritory is specifically for games provided by NetEnt. If he played games provided by NetEnt, then yes, he's on a difficult situation [which I assume BC will have it blocked from Iran by default], but BC have several providers, not just NetEnt, so there is a chance that he didn't breach any ToS, since he didn't play games that's prohibited for Iranian.
Normally, if a game is territory blocked by a provider you just can't blame the game, I had this on other sites that didn't allow a certain provider where I live. It didn't even load and I just got a message that "this game is not available in your region".
So normally it isn't even possible to play that game so I don't see any TOS violation as well.
But sometimes it is what it is. It's always a tricky situation with geoblocks unfortunately. I don't see any reason to violate TOS because of a game. If a game is not available in a region you can always find another one. Hopefully this somehow gets resolved but often there is more about it the meets the eye!