What happens if you shoot a rifle up into the air, does the bullet keep going on forever (well maybe in space)? No, here in the atmosphere gravity wins out and that bullet comes down somewhere. Really not anything different with a big anti-aircraft missile. What happens if that AA missile doesn't hit its target, gets jammed somehow, or malfunctions, it comes down to the ground as well.
What the MSM isn't saying much today is that Rus unleashed a barrage of air and ship launched cruise missiles again against more of the Ukie electrical grid. One of the strikes was against a node near Lvov. How far is Lvov (used to be a Polish city) from the current Polish/Ukraine border? About 45 miles. The missile that came down on the Polish farm was a S-300, an AA missile. Either it was a miss by the Ukies or the Rus launched a salvo from Belrus across Ukie air space. It doesn't really seem that complicated
But if the Poles want to call an Article 4 so maybe there can be an Article 5, be my guest. Field Marshal Boco can lead the combined NATO forward to wipe out the red commies once and for all. Napoleon launched his 600,000 man "Grand Armee" from Poland in the summer of 1812 (a majority of it non French), a good long march to Moscow. Not many made it back to Poland by March of 1813, even with the little Frenchman sitting in Moscow for 6 weeks during the late fall. Logistics typically suck for long strung out operations and then there is a thing called winter in that part of Europe. Napoleon on his retreat/route noted that bald men typically died of cold exposure over guys with hair. Go figure. Good luck NATO...