that would be pretty stupid so it's definitely an option
we can guess that 1. assad was on that plane, and 2. it did something that looked like a bad malfunction and 3. there are rumors of plane crash in the area. maybe it was some stupid reason like mechanical malfunction, or maybe friendly fire from russian S300 at Tartus, or maybe unfriendly fire from whatever SAM HTS now has. or something else
check matrix it's all in there