He can’t do that but I’m sure tomorrow he will dispel with the culpable negligence part of the manslaughter charge in his closing remarks.
From my understanding, to prove manslaughter one the state must prove not only that a person died who would not have done so had the defendant not performed some action which a prudent person would not have done, but also that a prudent person would have regarded the death as a foreseeable consequence of such action. I don't think that applies here.
Also, I wonder whether the defendant should be entitled to bring up the "clean hands" doctrine. To the extent that TM brought the physical confrontation upon himself, the responsibility for its consequences should lie with him rather than GZ. The state should not merely have to prove that GZ was at least "somewhat" culpable, but also that his culpability substantially exceeded that of TM. Even if the state could meet the first hurdle, there's no way it meets the second.