I think the reason the school hasn't suspended him is because he doesn't actually work there, so they can't do anything. The impression I got was that he'd be brought in as a consultant essentially.
I know I shouldn't be, but I'm kind of shocked because LGS is an extremely posh school. These aren't kids from economically disadvantaged backgrounds where the parents and kids can be bullied by the administration. It makes you wonder about what really happens behind the scenes anywhere.