Ollie was talking to Libra and one of the other girls - telling them that he was pretty sure they were safe and that Memphis would be put on the block. then Brian walked in the room and Ollie asked him to affirm that the ladies were safe.
After Brian left, Libra started to think it was odd that Ollie and Brian were so much in agreement. She suspected them of being in an alliance and asked the other girl (who has admitted to a crush on Ollie) if Ollie was aligned with Brian. The girl said that Ollie wasn't, but it was enough for Libra to start questioning people.
Libra and the girl confronted Ollie about how Brian has made promises to everyone. Once they convinced Ollie of the truth, he realized that Brian was not trustworthy and joined with the ladies to get rid of Brian. He thought that Ollie was using him as the front man and that Brian and Dan would have no problem dumping him.
So, Libra should have the credit for exposing Brian.
The trio realized that the only way to convince Jerry to put of Brian was by having everyone tell him the truth together - instead of using hearsay. You could tell Jerry did not like feeling ganged up on. Next thing we see is Brian being put on the block. I'm sure Jerry did not want to go back on his word, but he also had to have realized that Brian was using him and that Brian would not honor their alliance either.
