This is atrocious behavior. The perp deserves whatever he gets.
Not the first time I have heard of this sort of thing, but it is, thankfully, rare.
IIRC, years ago (late 70's or so) there was a case similar to this in which an anesthesiologist surrounded himself with drapes and orally raped his intubated patients. He got caught, but I don't remember the outcome of his trial. It was a long time ago.
It is truly hard to believe that someone in the room at these various institutions didn't have their suspicions. The ORs I work in are so full of activity that people are moving about at all times. Someone had to have noticed.