this chapter was

Is it confirmed that Garon is his mother's killer?

no, it's not confirmed. someone else mentioned it was the villagers that killed his mother,

I thought in the novel Garon said he literally killed her for no reason, and his great reason for hating Imae is ass (someone spoiled, Idk if it's true)

Oh nooo I was giving him the benefit of the doubt coz I don't want mc to end up with his mom's killer how very disappointing

That's what happens in the novel. It's weird, like he hates them but is fascinated and likes them... but yeah he defo killed his mum. It's a whole thing for mc coming to terms with loving the person who killed her.