Response:
Alan Futerfas, the attorney retained by Donald Trump Jr., confirmed he has spoken to the individual.
"Its very simple, Futerfas said. "The person was described as a friend of Emin [Agalarov]s and maybe as a friend of Natalia [Veselnitskaya]s.
Agalarov is a pop star and a client of Rob Goldstone, a music publicist who arranged the meeting with Trump Jr. Agalarov appeared in a music video with Trump when the Miss Universe pageant, which Trump owned at the time, was held in Moscow in 2013.
Futerfas said he has talked with that individual who came to the meeting with Veselnitskaya. "He is a U.S. citizen. He told me specifically he was not working for the Russian government, and in fact laughed when I asked him that question.
Futerfas confirmed that, for the purpose of security or otherwise, the names were reviewed but said Trump Jr. knew nothing about the man's background at the time of the meeting.
When asked about whether he had concerns, knowing what he knows now, Futerfas responded: I have absolutely no concerns about what was said in that meeting.
It seems to me that if you're a deep undercover KGB asset, you might not necessarily go around telling people about your status.
(But that's just my humble opinion. Could be wrong.)