In other words a spook.

And you certainly don’t want an agency asset floating around in the legal/prison system of another country, friend or foe.

Not necessarily, administrative, service, and consular staff are not diplomats but still receive varying levels of diplomatic immunity, typically just as it relates to their job. A CIA officer would be under the cover of a diplomat, no one would ever say that they actually aren't a diplomat.

https://1997-2001.state.gov/www/about_state/diplomatic_immun...