“It would take a pretty good missile to shoot down a 777 at 35,000 ft traveling 500 knts.”
True this doesn’t sound like a probable surface to air shoot down. More like an onboard incident.
Onboard incident right above a known Russian AA emplacement? Ok.
BOOK missile system? Shoulder fired missile isn’t capable of taking down a 777 at 35K ft.....but a surface to air missile certainly is.