Christopher Steele acted as an employee of the Clinton campaign. So does it matter that he is not a US citizen? It was really the Clinton campaign that was producing the Trump dossier, not Christopher Steele acting on his own.
"Agent" is more broad than "employee," and there is likely some legal mumbo-jumbo that includes the notion of "anybody who was compensated, directly or indirectly".
Otherwise, the DEM's just dismiss the allegation with "not an employee."
This case has money laundering, source laundering, and information laundering. Conspiracy up to the sky!
Lets add Mrs ohr to that equation