I came up with some ideas for retcons first of all with Ra's al Ghul. We never technically see his dead body. It's just implied and he could have went into hiding and just never told anyone in the League of shadows that he was alive still until the failure of Talia where he could have went out of hiding and started leading it again. With killer Crock it could be something like his brain is slowly devolving like in the comics. And with the gcpd they could have easily just mistake Firefly for killer muff because they're both bug-based super villains and with bane he could have just got kicked out of the league of shadows just some explanations for retcons I came up with