I know you can spout off his logic, but I don't think his suit will hold water. They didn't grant any other religion a student association devoted to worship.
Yea, I'm realizing now after reading the official press release, that it is his claim that they are directing resources unfairly.
If he can show that they are, then he has a case. Otherwise, if he's just demanding for muslim prayer sites just because, then he'll have a much tougher time convincing the HR board.