It seems the pilots were shot during their parachute down by the "Turkmen", who are a tribal faction that is aided by Turkey in their efforts to throw out Assad.
http://www.telegraph.co.uk/news/worl...e-Turkmen.html
As best I can tell, Turkey funds their because they are brutally efficient fighters.
I think their attitude is...."he just dropped bombs on us, so h's a dead man".
War is a nasty business. You have Russia and Iran backing Assad, and the NATO Nations in particular backing the Rebels.
This whole "Rebel" thing is confounded by who hates who more, some are Sunni, some are Shiite, they are kinda in that "the enemy of my enemy is my friend" thing at the moment. But, the minute Assad is gone, one of the two will star chanting....." My Gods bigger than your God" and the killing just continues..........
Just like it has for over a thousand years.
By the way. That Russian plane stood no chance against the F-16's. The are designed as air to air combat fighters. The SU-24 is basically a fighter bomber. Bigger, slower, and much more vulnerable in a dogfight.