Almost every embassy and consulate posted position around the world from every country and in every country has diplomatic immunity. Even many military members assigned to these positions have diplomatic immunity. For US passports, blue is a civ passport, maroon is a military passport, and black is a diplomatic passport with the immunities agreed upon with the country they reside attached.

It would take a DOJ international relations lawyer to explain this one. As it so happens, I just might send this to a lawyer friend of mine that did just that job for a while and ask a few questions.