"...I find the accused's actions in entering a dark room, assuming that she had meant to instigate sex and ignoring the fact she was calling him the other bloke's name utterly bizarre and implausible..."
But Lass, on the reported account, that simply isn't what happened. The account reported in the Metro says:
"...Then she grabbed me saying, “come on Zack” and I realised “she’s thinking I’m Zack” so I jumped off the bed and jumped out of the room..."
When realised she was in fact consenting to Zack, it became obvious that there was no consent for him, and he "jumped off the bed and jumped out of the room"!!
You can choose not to believe him Lass, but you can't jusg make up your own account of things.