[pmorici]

That isn't a differentiation that usually matters when applying the term 'spy' in general.

[beezle]

Actually, its a differentiation that most journalist and editors fail to make primarily because their publications sell better using the term "spy" instead of "(case) officer" for the intelligence agency employee and "agent" or "asset" for the actual spy that is being run.

Unfortunately, that disservice has existed for decades and is probably difficult if not impossible to break.

[Luc]

But it matters in this case, and it explains the confusion of the poster asking the question. A spy would not have been let go.

[pmorici]

The diplomatic immunity is what mattered in this case. If it was someone with American citizenship but no other special status it probably would have gone differently.