Bit late, but this is my take...
Harry played mega well. But Molly, Evie and Andrew played a game with massive logical errors - given Andrew was a traitor and knew who knew what, his failure to plan ahead let him down very badly and this was the massive difference between him and Harry. Evie also needed to plan ahead - as soon as she banished faithful jasmine, she basically crumbled knowing she might go next rather than thinking about the evidence she had to save herself - Evie relied on her social skills up to this point, so I think she prematurely gave up knowing how people would feel at the banishment without stepping back. It's hard in the moment, but Evie and Andrew did have time to prepare overnight.
Obviously Molly made a massive logical error - heart over head really, as she should have known that Jaz would not want a vote again if he was a traitor, so the odds were that Harry was the traitor if anyone was. Molly tried to be kind and loyal above good game play and she knew that she was doing that at the time, which is sweet and understandable for someone who hasn't had the chance to acquire a bit more experience (Mollie is young, plus has been either very unwell or a model, compared to the army training that Harry has had to put strategy above feelings - anyone who is screaming that this means he is a terrible person needs to understand that this is literally what the military train people to do).
That said, the person who had it in his hands to change the game and didn't was Andrew. He realised with 4 to go that it was him or Harry, because there had to be a traitor left and the faithful had to catch one for the game to end, and that really was one round too late. When Jaz piped up at the round table of 5, he wasn't mega convincing, but he was tentatively putting feelers out, looking around basically thinking "who is coming with me" and no one came with him so he stopped and became matey with Harry.
If, instead, when Jas spoke, Andrew had said "I agree with Jas. Also, if anyone desperately wanted to murder Harry, then why did Zac get killed last night? we banished Jasmine for nothing yesterday. I think Evie is faithful too and there is no point banishing her tonight, so the only person who stands to gain from the idea that the traitors tried to kill Harry was Harry and he must be the traitor", then he, Jas and Evie would have voted Harry out and Harry would have gone. Andrew might still have been voted out, given that he nailed a traitor, but he was guaranteed to go out anyway. He didn't realise this until far too late with the four players there.