Well, given the high-caliber of readers we have here, you guys identified most of the issues in the case.
Garrison was convicted of first-degree manslaughter. In that trial, the jury appeared to believe that since Garrison had disarmed Sharp of the pistol, he could have safely disarmed him of the knife as well. In addition, the court made no factual finding of whether Sharp was guilty of criminal trespass, so a key fact in Garrison's self-defense case was missing (Garrison also had a lawyer who apparently wasn't the best or brightest). The jury was also not impressed by the fact that both sister and Sharp apparently had regular drunken arguments of this nature in the past without anybody getting hurt.
Garrison appealed the conviction and the court of appeals reversed and remanded the conviction with instructions to the trial court to determine the following facts:
(1) Was the defendant's use of force excessive because he reasonably believed that he could have disarmed the decedent?
(2) Was the defendant's use of force excessive because he knew that he could retreat with complete safety?
(3) Was the decedent on the premises as a criminal trespasser?
(4) Was the defendant a person privileged to be in or upon the premises?
Garrison was again convicted of manslaughter in the first degree. The jury found that use of force was excessive because they believed Garrison's earlier successful disarm attempt showed he would have been able to disarm the victim again. The jury also found that the he could have retreated with complete safety (Garrison's ace lawyer made no attempt to argue otherwise), that Sharp was NOT a criminal trespasser, and that Garrison was also privileged to be on the premises.
Garrison appealed. The Court of Appeals declined to address the thorny issue of whether the jury's finding that he could have disarmed Sharp was reasonable since they found that his failure to retreat further after the first shot was sufficient to justify a conviction of manslaughter regardless of whether he might have been unable to disarm Sharp. The Court of Appeals upheld the conviction.
Retreat would not have been an issue had Sharp been a criminal trespasser; but because Sharp was found to also be privileged to be on the premises, Garrison was held to have the usual duty to retreat required by state law even though he was inside a dwelling.