Oliver's sudden distrust in Kara could also be tied to his experience in the virtual world, and also that before he was abducted, Kara almost killed him, Barry, and Wally when she was brainwashed along with the others.Thea off-screen deciding not to continue the fight with the others makes sense, considering in the Arrow crossover episode, she almost stayed in the virtual world where her parents are still alive and she was probably still feeling emotional from the experience.
What prompts him to do this? Doing the exact same thing he was mad at Barry for doing: altering time. Catharsis Factor: Cisco finally forgives Barry and calls him his friend again.He seemingly forgets that Barry intentionally changed time and caused far more drastic developments as a result, yet Cisco somehow sees this as similar and instantly forgives Barry. Cisco makes an accidental, completely benign change to history while with the Legends on a Waverider, and somehow comes to see how Barry wasn't at fault for Flashpoint because of how easily one can mess with time. The aforementioned incident with Cisco is rather poorly executed.It can be quite glaring for viewers who themselves were still mad at Barry for what he did or found him too Easily Forgiven by the narrative for what he did. Ass Pull: The episode puts to bed much of the guilt and blame Barry was experiencing over Flashpoint, but to do so, it stretches quite a bit of credibility.This is what gets him to finally forgive Barry. Author's Saving Throw: Cisco, who has been holding a blind grudge against Barry for creating Flashpoint and unintentional causing his brother's death, experiences the same guilt after realizing that he is one of the factors that brought the Dominators to Earth by altering the timeline.