Brexit was not on the agenda.
David Cameron did not expect to win in 2015. He thought Nick Clegg would save him from his promise on a referendum. But Cameron won and Clegg lost.
When he became Prime Minister he realised he would have to deliver. But he thought his colleagues would save from Farage. But Johnson and Gove did not.
It is now obvious Gove and Johnson had no expectation of, or plan for, winning. But they did all the same.
No one in the Conservative Party expected that they would deliver Brexit. But they did.
What does that say about their judgement? And whether they should nominate the next prime minister without that being voted on?