.... the guy was handcuffed when he was shot.
that is a definite problem.
Which is why in the thread on the case I suggested the "Anatomy of a Murder" defense.
That was a real case, tried in Marquette MI by an older lawyer I knew, Johnny Voelker, whose story is here:
Anatomy's "bio" is here:
The real trial is summarized here (last 2 pp. of 10):
Now, for the bottom line - closing comment by one of the jurors (end p. 10):
“I was thankful that the trial was over. I felt that the lieutenant was justified in what he did. I was a soldier and a soldier is trained to defend and that’s what the lieutenant did—defend his wife. I don’t think he was temporarily insane. I felt he had a right to do what he did. Why should he suffer the rest of his life to let a man do that to his wife?”
That is what I mean by "jury nullification" - you argue a legal theory as the direct defense, but the real object is to convince the jury of the indirect defense that you can't argue directly.