This shooting down of a Syrian warplane by the Israelis today is bad behavior on the part of the Israeli defense force and reflects bad behavior on the part of the civilian Israeli leadership. Leave aside conflicting claims by the Syrian and Israeli governments about what happened. The Israelis knew that the Syrian air force was attacking Islamic State positions, which are deliberately placed as close as possible to the 'Separation of Forces' line in the attempt to thwart Russian and Syrian bombers.
Yet an Israeli-U.S. bombing campaign, or even a joint Israeli-Russian campaign, or simply a U.S. campaign, would have routed the position without causing Israel to express worries about Syria violating the line.
Why wasn't this done? From all I have seen of Israeli war policies in recent decades, I'd say the ultimate answer is that the Israeli civilian leadership has taken to throwing away every high card they've been dealt.
In any case the Syrian pilot was killed, it seems during the plane crash. (AMN chief Leith Fadel reported earlier today on his Twitter page. "The video circulating of the alleged dead pilot is believed to be old," that is, it's probably not the pilot.
No word yet that I've seen on the fate of the co-pilot but reportedly the plane crashed in IS-controlled terrain.
Leith also reported today, at 6:54 AM: "Breaking: Syrian Army liberates Al-Bassali from Daesh in southern Al-Quneitra. SAA [Syrian Arab Army] is now at the gates of Saida, which is where the jet was believed to have crashed."