I do rather believe BJ has "Delusions of Grandeur" to some extent.
As on the now well known school report:
"Boris really has adopted a disgracefully cavalier attitude to his classical studies. [He] sometimes seems affronted when criticised for what amounts to a gross failure of responsibility (and surprised at the same time that he was not appointed Captain of the school for the next half).
"I think he honestly believes that it is churlish of us not to regard him as an exception, one who should be free of the network of obligation that binds everyone else."
I don't think everything he did was "bad" by any means, but rather that aspects of his character in the end were his undoing: I don't think he was "knifed in the back", rather that fellow MP's realised the consequences of his character would pull the party down, and in a way, they did.