This isn't just a "mistake". This is another example of his MANY actions wrt VII's false ecumenism. He taught the Church through his actions that these actions were Catholic in nature. I wonder how many Catholics he has taught that it's ok to kiss the book of a false religion.
Let me be clear I agree that was a mistake on his part but again, a mistake even an ongoing one doesn’t prohibit him from being a Saint.
I mean we know that declarations of Sainthood are considered infallible. So are you saying he was erroneously “made” a Saint (and thus Francis is not a valid Pope)?