I've read the transcript of the original trial.
Ched incriminated himself. The girl had absolutely no memory of going to or being in the hotel. She woke up with no idea how she had got to the hotel, having wet the bed.
The hotel staff called the police who then found the two footballers. Clayton McDonald and Ched both told the police that CM had been having sex with the girl when Ched asked if he could join in and both CM and CE said that the girl had enthusiastically said "yes."
This has not been disputed. Ched was convicted because the prosecution contended that even if the girl has said "yes" she was way too drunk to know what she was doing.
The digital evidence was not Facebook it was Twitter. A New York firefighter who had become involved in the 911 "truther" movement happened to read about this case and did some investigation. He found, in google's French cache of Twitter posts, tweets from the girl about "winning big."
http://chedevans.com/the-disputed-tweets