The Umbrella Corporation wrote:
Kirk shouldn't have accepted a challenge-to-the-death.
Kirk wasn't even told it was a fight to death until after he accepted. So the Vulcans, including T'Pau, actually tricked him into accepting.
Ignorance of the law is no excuse.
Presumably a Starship Captain, a representative of the Federation should know this.
Look at it from T'Pau's point of view. She must have wondered why Kirk would have accepted the challenge. Surely he didn't fancy T'Pring. So did he want to die or just kill Spock or maybe show off in front of T'Pau?
Maybe she just wanted to teach Kirk some sort of lesson by refusing Spock's request to deny Kirk''s acceptance of challenge.
So what is the law anyway?
Vulcan elder on Vulcan requires Spock and Kirk to fight to the death. She gives Kirk the option of backing out. Spock requests that Kirk backs out. Kirk again refuses. So Spock has to agree to obey the law of his home planet.
Legally is Spock guilty?
I think in TNG Picard says to someone the law of Federation overrides local law but that was on a Starship. I don't know what happens if a Starfleet officer is on a Federation planet. Does local law override Federation law? In 'Wolf in the Fold' it seemed to but that wasn't a Federation planet.
I know its not that simple, Kirk didn't know that it was a fight to the death and Spock couldn't control himself.