I'll just say if that was a self-defender deciding to use lethal force in that scenario it likely wouldn't end well for them.
Irrelevant. This is a police encounter. The police can shoot a fleeing felon if there is probable cause that there is imminent danger to the officer or the public. That's a simplification, and there are obviously many variables that can come into play, but no such authority exists for a non-LEO to shoot a person who is fleeing. (That I am aware of)