Wouldn't Ukraine have some stocks of Russian made missiles from the old Soviet days? It probably wouldn't be in either side's best interest to have purposely fired the missile into Poland.
Zelinsky has been all over everyone (NATO) for more money and more weapons.... very recently.
If they fired into a border area... perhaps not knowing people would be in that area.... he sure would have better footing to
claim that now is time for something to escalate.
I do not trust Zelinsky any more then I trust Putin.
According to another untrustworthy politician Biden...
Biden says it’s ‘unlikely’ the missile that hit Poland was fired from Russia
This in response to : Early Wednesday morning, Polish officials said a “Russian-made missile” landed on its soil, killing two people.https://www.cnbc.com/2022/11/15/biden-says-its-unlikely-russia-fired-the-missile-that-hit-poland.html