You miss the point completely, McDonald and the girl met and made the decision to go back to the hotel. The inference from that is that two consenting adults decided to maybe have sex. Most people know that drink takes a while to kick in, but the fact is that these two met. Evan let himself into a room, where one could ask, who invited him? What was he doing there and at that time what state was the girl in, did she know that Evans was even in the room? She has no recollection of sleeping with Evans, therefore after hearing the evidence, the jury decided that she could not give consent and therefore it was rape. Macdonald picked her up, therefore it was more of a grey area of doubt as she consented to get into the taxi and go back to the hotel.
If you read my post, you will see that I haven't missed the point. According to the evidence, it was over an hour from the time of her last drink to when she then went back to the hotel so the drinks she had had would have taken effect by then. She has no recollection of sleeping with Evans but you have also failed to mention that she has no recollection of sleeping with McDonald. In fact, she has no recollection of any conversation with McDonald!