@itorres How do you know it's comparatively isolated and circumstantial when you "have no idea what the fuss is about"?
Also, as others have pointed out, both in your replies and in many other things written about this (which you would perhaps have seen if you had read up about the "fuss" before posting about it), this is not the first time Fosstodon has gotten in trouble for stuff like this.
An instance can earn sanctions from a pattern of "small" incidents; it doesn't have to be a big bang.