If it were true (currently I don’t think so) we’d have a warm spot on FIRMS and civilian reports of a transport plane coming down, but nobody has reported one so far. (However, Syria is likely to have so many warm spots currently that a private researcher may be unable to count them and make sense.)

However, assassinating someone with an air defense complex while retreating / evacuating yourself in face of an advancing opponent - that’s unreliable. (Russians were last seen evacuating their air defense systems and flying away with what could be taken along, but rebels did get some really interesting items.)