Let me express it this way:

a) IF (a big IF), the Russians fired any S-300s from within Belarus: official Kyiv never mentioned that. It did mention the S-300 attack on…

Let me express it this way:

a) IF (a big IF), the Russians fired any S-300s from within Belarus: official Kyiv never mentioned that. It did mention the S-300 attack on the Kharkiv Oblast, though.

b) By best will, the target of the Ukrainian air defences was a Kalibr approaching from the south, not from the north. While,

c) photos of the missile wreckage from the crash site in Poland are shown parts of a 5V55.

From my POV, sorry, it's pointless to discuss alternatives.