This would be unlikely. Stipulating that ordinary xHamster users are watching the ordinary videos for the thrills... how many of them watch every video to the end?
Why do you believe this? It's not at all similar to how the regular user base watches videos. Compare PornHub's in-video display of how popular various timestamps are.
I never thought about the fact that the reviewers can have bad intentions. Interesting....
Although, to be honest, typically videos are buffered and even cached from the browser, so logging incoming web traffic won't help there.
Preventing outgoing traffic might help. Preventing storage would be interesting. I think those machines need to be really just terminals where you can't do literally anything but click yes/no and go to the next in the queue. It'd be interesting to know how they do it.
My point is - doing this like you said "quasi-legally" must be the worst way of doing it, as you're giving the company all your real details to be employed - the very second anyone suspects you're doing it for the thrills(maybe you are the only employee who actually watches every video to the end?) you'd be in deep trouble.