Yeah, but he refuses to acknowledge the possibility that Penelope likes him, so that's the most likely possibility in his mind xD
His thought process was kinda like: Penelope is nervous around him --> Olivia said something to turn her against him --> If she told the truth, Penelope would probably be more up front than freaked out --> She is freaked out, so it must be something else --> Olivia lied --> Solution: Olivia lied to destroy their friendship out of spite

He's definitely an over thinker, haha