There are several possibilities.
1) Ukrainians used defence against Russian missiles, it could have made one go off course.
2) Ukrainians used defence and one of their own missiles missed or overshot or somehow deflected into Polish territory.
3) The Russian missiles were faulty and missed their target.
4) The Russian missiles weren't faulty and hit their target !
Numbers 3 and 4 are the least likely.
Number 2 is most likely.
Putin's a total [email protected]
but even he would know that if they targeted Poland, he'd be done.
It wouldn't involve nukes but it would likely start with a large build up of Polish, USA and British forces representing NATO, at the border of Poland and Ukraine. Hopefully that alone would be enough to cause the further retreat of the Russian army, with or without Putin's consent.
If that wasn't enough, a reason would be created to defend Poland by entering Ukraine. Seeing a strong NATO force moving into Ukraine would, again hopefully, be enough to send the remnants of their army packing. Probably only the Wagner group would remain but they'd soon disperse to somewhere cosy.
I've watched hundreds of hours of reportage from Ukraine from both sides. Some of it suitable for snowflakes, much of it not for snowflakes and some that aren't public domain.
As far as I can tell, most Russian soldiers aren't up for the fight. They have no food, no medical help, no equipment and no moral.
The Ukrainians are fighting for their homeland, the Russians are fighting for the deluded ideals of a dictator looking to create a legacy. The only legacy he'll leave is that of becoming Hitler MkII.
Some quality Russian hardware.