And now you show me where it was said that "chilling on the couch" meant the end of the sexual encounter? You do know that he used the exact same phrase before that evening, right? For him chilling was actually making out and having oral sex, something she did partake in. The suggestion to put clothes back on can be very well be seen as an attempt by him to have her calm down (which again happened before that evening).
Sexual assault actually involves one party being aware that there is no consent, either by cutlural standart, law or being told by that person. Her previous behaviour inditated to him that she would be alright with sexual acts as long as it does not involve intercourse.
The whole thing is first and foremost some pretty grand miscommunication, because they both thought they would get different things out of the evening. The way he handled it was rude, but not criminal.
I don´t see the relevance to the Ansari story. In her story the boundaries are set as they should be. Clear and in advance. If Grace would have told Ansari, that he could not expect anything sexually from her, especially before entering his apartment, he would be indeed guilty of sexual assault. Instead she took part in everything outside intercourse, which gave him the impression that she was alright with exactly that.