I have a teacher that said slavery was good

Ok so this is about to be an absolute monster of a yap session so get ready. I DONT AGREE WITH HIM MODS.

Alr so imma get straight to the point because I, too hate ragebait and clickbait. So the guy I'm talking is by history teacher and we're gonna call him Mr. Asshole. So we were learning about the colonization of South America and the slave trade. And now for the past few days Mr asshole had been been hinting at what he was trying to say and the entire class knew he was a bad person already. But one day he starts going on a bit of a tangent and he says, "it's like I wanna tell you something that I as a teacher cannot say" (which means he shouldn't have said it in the first place but whatever) and then he says, "slavery was good" and the whole class went completely silent. And I guess it was then that he realized he fucked up because after quite a long pause he adds, "at the time". And as you would expect in a class full of high school students, people start murmering to eachother and Mr asshole screams, "I SAID AT THE TIME" to this one kid, like that would fix it. Anyways he's done other stuff before and I heard a rumor that he's being investigated. The crazy thing is he's been teaching for a good 15 years so I'm not sure why he wasn't investigated sooner.