Potato potato.

That's it though. That's all anyone has said about it. I really don't want to come across like I'm defending Whedon but he was mean and nasty to a lot of people on his set and that might be all that quote means. Interpreting it as inappropriate sex stuff is entirely extrapolation. Just because you can think of a worst case scenario doesn't make it so. Again! This is not "Whedon was a good guy." This is "that's a really big accusation to pull out of one out of context quote."

Edit - to be completely clear, I was aware he was not allowed alone with Trachtenberg. I just find it troubling that people automatically assume the reason why was sexual abuse, to the point where OP was stating it as fact. It's jumping to conclusions. While there is much documentation on how emotionally abusive he was to the "out group" on his sets, which included Trachtenberg, nobody has ever actually accused him of assault, so people are legitimately just looking at that one quote and assuming the worst. There's so many reasons to dislike the guy, we don't need to start making them up.