I think a difficult personality is a necessity for the role he is performing. While a difficult personality absolutely is not and must not be a reason to condemn someone, the good such people perform doesn’t mean anyone should have to put up with their antisocial behaviour, nor that he in particular gets a free pass from the court processes which caused him to end up in the embassy in the first place.

Same rules for everyone. None of us are pure saints, and even those of us who are pure evil [1] should only be prosecuted for acts which one can reasonably believe them to be guilty of before a trial actually demonstrates the quality of the evidence.

[1] by which I mean dark triad personalities, not religious/utilitarian/etc. ethics.