[user104658]

Originally Posted by Alf

So what happened was it was Ukraine who did it and then they lied to try to frame Russia for it in a bid to escalate WWIII

Do I have that right?

Not really although of course the blame-game is being played - the suggestion is that it's a SAM (surface to air missile) fired by Ukraine to intercept Russian missiles, that has gone astray and landed over the Polish border.

I personally would call that shared responsibility; Ukraine ultimately has to share responsibility if equipment has gone wrong, but Russia is partly to blame for engaging targets so close to the border, as they know the risks.

These things aren't all that unusual, similar has happened plenty of times in the Middle East (usually Americans firing the rockets). More commonly missiles aimed at military targets accidentally blowing a civilian building to bits.

NATO countries have a vested interest in giving the benefit of the doubt if both sides are claiming this was an accident, because if they don't allow "it was an accident sorry!" to be an acceptable excuse, then they'll have less wriggle room themselves when they inevitably next do the same.