I’m not finding a man with initials of S.M., that was also a spy and is affiliated with Cambridge.
S.M. is wrong, from what I see. S.H. is what he should have said. Stephan Halper is connected to British and American intelligence. He worked for several Republican administrations. He is not connected to Trump. However, he and a few others seemed to have deliberately targeted Papadopolous and planted a rumor with him, which he drunkenly spread in a set-up meeting with Alexander Downing (Ambassaodor from Australia, over in Britain, and the rumor was that the Trump campaign KNEW that Russian had thousands of stolen Hillary emails. Then THAT incident was used to turn around and start a deep state spy campaign against Trump.
I think maybe people are conflating SEVERAL individuals playing different roles in a conspiracy, with the belief that a single person is a mole by the FBI inside Trump’s campaign and/or the WH.