Apparently, there is indeed a second floor at that bar and that ends up to be the main reason why Cassidy is able to beat Irish.
Because of how dim the whole place was, it was hard to notice at first. She won't be able to find out had she not stood on that stage. Now, it made sense why she got a louder round of applause.
Performing after Irish turns out to be a good thing. It was actually the blasting sounds of cheering and shouting earlier that attracted a larger audience. With that, more people got to see the next performance, thus the louder round of applause.
"Oh, you lost, Irish-"
"I know that, Olivia! I can see it! Ughhh...!" Irish groaned in miff before storming away.
"Let's go! I want to drink right now!"
"What about the bet?" Olivia calmly asked with her arms crossed, already used to her fits of pique.
"She can just walk up to me and be done with it! I don't care anymore!"
Here's the answer, everyone. He had no idea at all -
Like how he had always been. Yep.
Then again, he's always a clueless dolt, and he isn't that fond of ladies to begin with.
I've read a comment about Sophie putting a drug in his drink, but she did not do anything like that. She's not the only antagonist here.
(Why say he cheated when he did not even know or permit it? He was forced. That's the underlying message. But I support different interpretations from the readers ᕙ( • ‿ • )ᕗ)