Legally Jenny can claim that as rape and actually win the case. But what is causing the rift about the scene is something else. Because there are also things that show Jenny was just as much into it as the others. Ofcourse you can't prove that in law.
But these are the evidences from the scene which make it a bit ambiguous or as is being said, treading a fine line.
Jennifer herself was interested in Andrew's dick. Ofcourse it is just a fantasy, doesn't mean she should actually do it.
Just one minute. However we are told in the scene that 1 minute has passed quite a while back before Aiden decided to join. Now the question is if this was all against Jenny's will. Why didn't she stop it herself. It wasn't like she asked Andre to stop after a minute and he didn't.
Jennifer was in ecstasy and there are few more dialogues in the scene emphasizing that she was also turned on and enjoying this.
She even assisted Andre in stripping her, is it the sign of a girl being forced to do this completely against her will.
In the end, The way things initiate are clearly around rape, however Jennifer's behaviour, actions , expressions throughout the scene all convey the contrary. And just so no one misunderstands, I agree that legally this will be rape. However what Jennifer is feeling from this and her participation is also reflecting a contrary scenario. Hence why we see the opinions on the scene vary.