Interesting. I really don't know how they can claim he didn't do exactly that. He ran away until he heard a gunshot behind. He turned to find Rosenbaum charging at him reaching for his gun.I looked up the law. https://docs.legis.wisconsin.gov/statutes/statutes/939/iii/48
Relevant portion bolded.
So it's pretty plain you can regain a self-defense claim, even one involving deadly force.