This is an untrue statement. Under WI (and many others) law, while provoking, or threatening, a third party can be it's own crime, once he disengaged and ran he regains the right to self defense. Once one party communicates the desire to stop the engagement everyone is supposed to stop. By pursuing and cornering Kyle, Rosenbaum became the aggressor and Kyle had the right to defend himself.
And that's if you believe Kyle decided to be a southpaw for a sec and pointed the rifle at anyone.
That’s a great argument on the evidence and in general - unfortunately the prosecutor was not so generous, and there is a non-zero possibility the jury believes his version of provocation which was offered against a jury instruction quite different to your explanation of the law of WI.
It is absolutely true to say that if the jury believes the line about pointing the gun first, he’s in serious trouble. Because that means everything about his encounter with the first decedent turns on exhausting all avenues of retreat. Will they buy the provocation arguments?
Hard to say, but sure is a good reason to think it’s better to avoid these situations in the first place.
