This guy is a civil servant. There is a code of conduct for all civil servants to follow. From what I am seeing, I don't believe he is following all that he should.
To tell his staff to speak up, is something that is fine, internally. Even then, a lot of staff will not speak up for fear of being taken to task by superiors. It's the way the civil service works, even though the public may think otherwise.
To even talk publicly about working issues, or to have the contents of an internal e-mail made public, does not equate to public service. In the ordinary course of events, that would lead to the invoking of internal disciplinary procedures. However, whether that applies to a diplomat is another matter altogether.
'Boots on the ground' does not bring with it the right to talk about anything and everything concerning the job, and the complete range of duties, and the in-depth duties carried out. It is why civil servants sign the Official Secrets Act...