Changing one's mind about him can take a while.

With the benefit of hindsight, it certainly took me longer than I am happy with to change my mind about him; to be specific, I should have more radically changed my opinion of his personality when he libelled that cave expert in response to being told a submarine wasn't going to help, I should have recognised that only someone with a very fragile ego would react that way, that it wasn't just a blip on his record but something deeper.

Anyone working at Twitter at the time of its acquisition could have found themselves in such a position.