It didn't appear to me she was ever presented to Rudy as being 15, in fact, they even take a drink before going into the bedroom. And right after she was taking the mic. off his shirt, he did appear to be putting his shirt back down.
However, the fact they had a drink, went into the bedroom (when they could have easily taken off the mics. & what not, there), the hand placement, and asking for her phone & email, it does look very suggestive if they had allowed the scene to play out longer. Sacha claimed he stepped in b/c he has a legal obligation as a producer, to keep everyone safe & did not want to put her further into such a setup.
So, personally, I think it is overblown & Sacha did it to bring forth attention to the film (esp. since it happens directly at the end of the film). I think the most damning part of the film is the rally more than Rudy.