“That was a Uke doing it to a deserter, and they saw a chance to make some propaganda.”
I believe that. Russia is being super careful to not do anything that can be construed as a war crime. They know the US and UK eagerly broadcast any propaganda Ukraine can produce.
Ukraine knows ir, too. So they are masters of false flag stuff. Always have been.
This is purely an information war. That is the NATO main tactic.