Just as some other points to consider, Putin had a little historical precedent to use as a smokescreen when he alleged a possible false flag attack: namely, the long history of US false flag attacks and misinformation. Again, doesn't absolve the Kremlin of jack shit, but I feel that a lot of people who are so self-righteous in this sub are simply lacking in historical schooling.
Gulf of Tonkin -- NSA falsely blames North Vietnamese for nonexistent attack, allowing US to enter war.
Church Committee findings - FBI admits to using agent provocateurs from the 1950s through 1970s, to cause attacks which could be blamed on communists.
2001 Anthrax attacks -- White House pressured FBI to blame anthrax attacks on Al Qaeda
Syria, 1957 -- CIA (and MI6, so both US and UK) stage an Eisenhower-approved set of false flag attacks by Islamic extremists, as an excuse to topple Syrian government
Iran, 1952 False flag attacks by CIA operatives posing as communists are SUCCESSFUL in staging a successful coup.
Operation Gladio -- More cold war false flag terrorism perpetrated by CIA operatives, in Italy and cold-war europe.
Operation Northwoods -- While this one didn't go ahead, the US Joint Chiefs of Staff signed off on plans to false-flag Cuba by blowing up US civilian airliners or boats. Also planned to blame Cuba if John Glenn's rocket blew up. Only stopped by civilian leadership. The fucking JOINT CHIEFS signed off on a plan of US civilian murder as a pretext for war.
So, maybe there's more you need to take into consideration. World politics is dicey, and there are no angels. But their may be no demons, either. Just people with too much power making stupid mistakes.