It they are male it's beyond awful that they're being described as women. I just can't fathom this, surely they need finding before they do it again? What if another teen gets assaulted in the interim?
It's not just the heights. The story mentions him waking up, the poor lad was obviously made unconscious. That works if you're a man raping someone. I can't see how it could work for a (incredibly rare) female sex offender.
The only motivation I can think of for two actual women to do something like this is revenge or humiliation, not sexual kicks.