Few random thoughts
Just a few remarks
Given this accident location I'm pretty sure that flight was within both IDF and Egyptian military radar range (maybe even USAF AWACS). Any SAM launch (if there was one it wasn't a MPADS for sure) would have been spotted.
Another point is the amount of information - not necessarily relevant btw - that can be inferred out of ADS-B. Many have clamored for real time flight tracking... we are getting quite close !
Lastly a question: who will be investigation this (regardless of ICAO regulations) ? I feel that French BEA might emerge at some point... not sure the Russians would be happy about it but it still might be the fattest / most relevant approach.