I don't know how viciously Junta bounced Costin's head off the ice, whether or not Costin was unconscious at the time, nor if those blows were the fatal ones. It seems to me that all of those things should be taken into consideration. But I do know this: in the middle of what you might perceive to be a life-and-death struggle, you ARE NOT obligated to take the advice of the nearest hysterical woman.
You are obligated not to keep pounding someone until he is dead. That is what Junta did. That is what the multiple witnesses testified. That is what the jury heard. That is what the defense could not dispute. That is what makes it manslaughter. That is why Junta is where he should be.