is insulting someone post lobby bannable?

just said our jungler had downs, but that's closely related to calling someone retarded so I figured it could class as hate speech. I made sure no one but me actually saw it (waited for everyone to leave lobby) but I was just frustrated as shit and needed to vent. at least that way, I know I didn't tilt anyone else with flaming.

I know for a fact no one saw it, but I just hit honor 4 and it would be a shame to lose it because the IFS picked it up anyway.