Her description sounds like a drug was put into her very first drink. Since it's the next day, have the police done a toxicology report?
If the toxicology report came up negative (no drugs), would you go to trial? Would you convict?
Depending on how many hours have passed, most toxicology reports will not detect most "date rape" drugs. That is not conclusive proof she was not drugged. Moreover, she didn't claim conclusively that she was drugged, only that she immediately felt woozy.
She says she remembers saying "no" and pushing him off. He even confirms that part but didn't believe she really meant it. She says she blacked out. He says she later consented.
Chances are extremely high that official action won't go beyond questioning and releasing him. It is highly unlikely that the complaint will result in a prosecution, but it might make the news.
Who do you believe?
I don't know who to believe. Indeed, I would prefer to be agnostic on a situation with so little evidence. If you say 'I don't know', you can't be wrong.
I do know that if I don't know what to believe, I would not convict someone on that basis. "I don't know what to believe" does not equal "Beyond reasonable doubt".