Did we all forget Zane also made fun of laurance
see i hear you but the arguement is less about whether it was wrong for laur to make fun of zane in general and more about whether or not its acceptable for laurance to call zane names based on zane's bad eye.
for context, zane's mean nicknnames for laurance are "little laurance", which is a great use of alliteration and so vague i geniunely cant tell if its intended to be a short joke, a small dick joke, or just generally condescending, and "stupid laurance", which is just straight childish. its not nice but its not like he's calling him laurphan or some other personal attack that would justify laurance's behavior.
also important to note that laurance is the ONLY character who intentionally makes fun of zane's eye. it's established pretty early on (iirc same batch of pixel painters that laur started the one eye thing in) that other characters who regularly tease zane (ex. garroth and aph) are aware that it's a senstive subject and get all apologetic when they do it accidentally. even gene, who picks fights with zane like it's a sport, never brings up his bad eye. it's basically the only line people won't cross when they're clowning on zane.
there are so, so many valid reasons to bully zane that laurance could base his nicknames on, we doesn't have to chose the blatantly ableist one