The entire situation decides intent.

While I don't subscribe to this "general/specific intent" model, your own arguments demonstrate otherwise. Your arguments below rest on the premise that one of the parties started with general intent, and then switched to specific intent. Two parties are interacting. Their intentions change in response to eachother's actions. The entire situation doesn't describe intent; there are intentions behind each and every individual action.

Because neither we nor any party involved can know the contents of any mind but their own, none can actually know intent. I reject the "intent" model specifically because the minds are unknowable to anyone. The "justification" model resolves this problem: None of the parties needs to know why the other party is doing what they are doing; their actions provide sufficient context to speak for themselves. Still, for convenience, I will try to frame my position in your terms.

He throws the drink in her face, general intent.

Good. You concede that the throwing of the drink in the face was what you call general intent. I've readily conceded that this act was provoked, but unjustified. We now appear to be in agreement that the throwing of the drink was not particularly important to the events at hand. You deem it a misdemeanor. I've said that it could qualify as disturbing the peace. We're basically on the same page with regard to the throwing of the drink.

Once he physically interacted with her that is no longer general and it switches all his actions to specific intent.

His first physical interaction with her (after all the "general intent" actions involving the drink) was being struck in the face by her.

We can safely presume that Her specific intent was to cause him harm. We can safely presume that his specific intent was to stop her from harming him. The "intent" model shows the same thing that the "justification" model shows.