Given the context of an intelligence officer knocking on an unfamiliar person's hotel room door unexpected and asking them to defect, I think "salaam habibi" would strike most Farsi speakers as a bizarre and malapropos greeting.
"Hola amigo. I’m from the CIA, and I want you to board a plane with me to the United States."
I see it as an indicator of careless journalism that the author is citing an unnamed source "familiar on the matter" about a 10-year-old conversation that he seems not to have transcribed into the right language. I put it into the same category of people who ask what part of Mexico the Puerto Ricans are from.
I get what you're saying, but "hola amigo" is a really bad example of it. There are 40 million Spanish speakers in the US and tens of millions more use Spanish phrases routinely as a personality quirk. "Hola" and "amigo" are both words that I'd expect most Americans to understand, and I wouldn't bat an eye if a CIA agent greeted my in that way, assuming the context wasn't too formal.
Maybe a better example would be... well, if they put their hand over their heart and said "salaam habibi" to an American scientist.
Yeah, maybe I watch too many movies, but "hola amigo" feels like a totally appropriate greeting before you're about to do some shady spy shit. I think that it's actually a good greeting because it indicates to the other person that this interaction is about to be a bit informal.