I think a lot of it is down to the way you say it, and also your reputation. Nobody would for instance give Lisnaholic an infraction for calling someone let's say stupid or clueless (which he would never do anyway) whereas if butthead said it the chances are it might be looked on more seriously. History has a lot to do with it, also context and I think in general you would expect to get a warning before an actual infraction: the mods don't generally go aorund stamping on people's right to free speech (they usually drive over it, then reverse to make sure they got it the first time --- infraction on the way!)
In the end, who you are may, or should, and probably does, have a lot to do with how you're treated,though I am surprised Steph got an infraction for that, although I don't know the details. Probably just jealous of her beauty...