Escalation is irrelevant. Talk to me about justification. Start with her grabbing of the glass. Proceed to the throwing of the drink. Proceed to her standing up and striking him. Talk to me about any issue of justification of at least these three acts.
Her initial grabbing of the glass was unjustified. There's an image of a post (supposedly) made by her where she discusses the incident. Her statement confirms that her grabbing of the glass was not justified.
He did escalate, after her provocation. He threw the contents of his glass in her face. Unjustified, but provoked: his conduct would likely be excused.
Having provoked the throwing of the liquid, she was not justified in striking him. She escalated anyway, unjustifiably. I believe you used the phrase "specific intent to cause harm" - she escalated to that point. Her conduct here justified a forceful response to stop her from striking him. He pushed her backward, she fell over her seat to the ground. She tried to get up to continue her attack; he kicked her back down, and attempted to retreat. That's de-escalation. Even if she had been justified, his retreat ended justification she would have had.
She escalated again, this time to unjustifiably threatening him with a deadly weapon. Again, she justified a forceful response to stop her new attack. Again, he pushed her away. Again, he retreated.
What part of my analysis of justification do you believe is flawed?