RJM-sorry to hear-false accusations-I'd sue him-it's the American way.
Seriously it is terrible. Me personally, if I knew it was a false accusation, and this had something to do with my son's character (ie drugs, crime, ***, etc) I probably wouldn't say anything. I would kick the door down in his office and break his jaw-but I'm known to be hot headed.
Back to the question about the closed door policy. I think he should have to talk to your son and explain himself ESPECIALLY if they are truly false accusations and it had something to do with his character. But if this "closed door" policy is known, and especially if it is written, have him talk to the ad or the principle instead and go from there.
Incredible. Coaches benching players for being questioned-yet in another thread it is all but right out said-little things don't make a difference the best players will be on the field.
Good luck to you.