“Could be as simple as someone had an axe to grind against him.”
That would be my assumption as well.
People often want to attribute these things to political differences or some sort of ideological struggle, when most murders are for person resentments and grudges.
And the uncontrolled free-for-all that prevailed in the Kiev area in the weeks after the war - they gave out AKs to everyone and there were murders every night that were covered over as “executing traitors” but were much more likely gangland slayings and score settling.
Imagine if the Russians pulled off the airborne assault of the Antonov Airport? They almost had it. So at that moment in time, it appeared like the government in Kyiv was going to fall apart and the Russians were going to conquer the country.
So literally, it was the "Wild West" at the time.
Instead the Russians botched the Day One attack. And the Ukrainians were able to counterattack the Russians in Kyiv.