
Thankfully I've never had one actually reported - much as to my horror, I had one who wasn't good in the ring at a local Fun Match. She was just not placed!! And needless to say that was it for her show career!! So as far as what steps the KC might take, I think maybe you should talk to them? I'm not sure, depending on what caused this to happen, I'd bother to carry on showing this dog - and if this IS true aggression, certainly not breed from it. Could be something about this particular judge spooked him/her? But I'd suggest it would have to be pretty serious for the judge to actually make a report about this dog.
ps I have had some 'known' judges be rough with my hounds in the ring - I pretty soon realised who of the judges in my breed did this, and they went into my little black book - fast.