If Gattuso did it on purpose he is a cheat. Therefore the ref was right to give a penalty which he did. Dudek also cheated, however the ref did not punish him, despite the fact that was the refs only job during the shoot out. YOu may not like the word but anybody he purposely breaks the rule is a cheat. Disguising the fact has nothing to do with it.
A murderer is someone who kills somebody regardless of whether they admit it or try to disguise it. A cheat is somebody is knowlingly breaks the rules on purpose.