OK, I can accept that. But on the other hand, I'm thinking that if there was institutionalized rape there, it couldn't have gone unnoticed this way. Or could it?

Good question. I would suspect that he did know about it, or assumed it happened, or at least wouldn't be surprised by it. I think the men recruits would probably talk about how of course the top guys were sleeping with whatever cadets they wanted. But it was probably also easy for him to just not think about this translating into young girls getting raped against their will on a regular basis, and it was probably easy over the years to not think it could have happened to Elizabeth.