Unless he claimed to be straight (and tried to rip people off with "going straight" seminars), it's not an issue. He wasn't exposing secrets. He was exposing deliberate deceptions which were used to manipulate other people into changing their behavior and beliefs.
He claims that miracle workers should put their claims up against a rigorous test. Fair enough. I wouldn't care if he was secretly (say) a Buddhist, as long as he didn't claim he (or anyone else) could work miracles. Faith in a higher power has a wonderful placebo effect - it's empirical. It doesn't mean you have to rationally accept it.
