If a guy keeps pouring water on a woman to piss her off, does he deserve to get hit?

My friend said her boyfriend kept pouring water on her to piss her off, and ended up pouring two gallons on her... well, that’s a lot... maybe she said liters? Point is, he poured a lot of water on her. She ended up hitting him for it. She told me that her therapist and therapy group said it wasn’t right of her to hit him for that... Is it wrong that I think it was totally right?

I think her therapy group is thinking in legal terms. And so am I lol. I really think that the bastard deserved to get hit for that, even from a legal standpoint.