“Spaz” as in to “spaz out” has always meant crazy or some variation on that where I grew up, though I haven’t heard it in ages. I suppose it is ableist, and I suppose we always meant it that way, I just never thought of a person with a disability when I said it. The flip side of that is, by so casually likening someone to a differently abled person in a prejudicial way, one demeans the differently abled person, even if they weren’t the target of the ire or the ridicule.

So we were definitely in the wrong for using it.