Well, people forget also that Assad shot down a predator that was being used to target ISIS. So targetting ISIS was not all the time popular for Russia and Assad, especially if the US was doing it. Point is that they are happy about Obama’s incompetence.
So the Syrian military shot down an aircraft flying over their territory without permission, owned by a country whose official position is to overthrow their government? Shocking!
Russia is the only country legally flying over Syria, aside from Syria of course.