That's a good moral stance, credit where it's due. Yet I don't know how practical it is to take the word of a Russian mayor at face value, with no input from Ukrainian command.
One other thing that doesn't sit well with me is the way onlookers treat Ukraine as their 'protagonist' in this story because they're a plucky underdog with a morally just logic for defense. I think it puts too much on Ukraine to hold them to the standards we would/should be holding our own countries, many of which no saints.
It doesn't sound like Ukraine to just attack civilians, that doesn't help their war aims. Attacking civilians is something Russia does because it does relate to their war aims; namely, genocide.