Exactly what I was about to say. If it had been a man slapping her everyone would be calling him an abuser. I hate it when they say that women can't be abusers or that violence between women is not abuse.
It's an ongoing issue that I don't think will ever be resolved, unfortunately. As soon as I see a girl or woman hit or slap anyone out of anger or spite, immediately whatever emotion I felt towards them turns to dislike and they lose my respect. I didnt like Achi anyway because she's your stereotypical get-in-the-way female character and I am certainly not a fan of yuri, but that slap did me in.
I really hate it that women think it's okay to slap people just because they're women. It's still violence, it's still abuse. If a guy did that, the cops would be called and he'd be spending the night in jail but a women? Nope. They can get away with that shit. Not okay to slap someone people! I don't care how hurt or upset you are. Grow up and handle it like a civilized human being and an adult.