The debate on Michael taking vengeance in an enraged state is largely moot, to my mind. I don't see TWG allowing him to arrive late to the party, if only because there's a real chance he might jeopardise the sword in such a fashion.
I do see him arriving just in time in a position to defend his daughter if she were there against her will.
The fact that she faced the consequences of her actions of her own free will, made the choice to "repent", knowing that the odds of her surviving were minimal, and Michael still arrived on time suggests to me that had she been dragged there against her will, there's not a power in the verse that could have stopped Michael standing between his daughter and the executioner's blade.
He would not be there to punish the WC, or deliver vengeance; he'd be there as a protector, or not at all.
