He's not and never has been on the committee. His wife is. And no one has been kicked off the committee.

If it's credible, why hasn't he been convicted.

Because building a case strong enough to stand up in court in situations like these is really hard and the police/prosecutors have decided not to priorities it.

But the core of the matter isn't really the sexual harassment, it's the fact that the Academy apparently knew about several cases of both sexual harassment and, more importantly, possible financial fraud/corruption involving this individual and instead of dealing with it, decided to protect him. The sexual harassment charges are just the events that brought these more serious charges to light.