No. Just no. Russia is invading. You can't, in good faith, blame the invaded for the casualties. The same way you can't tell a woman that she got beaten because she refused to have sex.
I can understand it's not a black and white issue, but this is the laziest propaganda imaginable. You want to stop the casualties right now? Russia retreats to their territory at this very moment. It's that simple. Keep trying to invade the country won't reduce the casualties. Now you will take your whataboutism card to say it's your time to do some killing. Or say that US allying with Ukraine and Russia taking my force is basically the same.
You think the invasion is rightful so the deaths are in there fault of the defenders? Happy that Russia reports low civilian death ratio? Fantastic, you have now used the same argument that all other atrocities used. I'll also oppose the ones you oppose BTW not only the ones that fit my agenda.