Much has been made of Mace Windu using tactics that border on dark side useage, but what about Yoda. There are many instances in the war that show Yoda to be a ruthless impulsive Jedi as well. He lops off the heads of the two clone troopers as he is about to be attacked. Why couldn't he use the force push back that he used with the guards in Sidious' quarters and not kill those two guys? He also throws his lightsaber into a clone's chest. That doesn't seem very jedi-like, either. I think Yoda knows how to walk the grey line that is Dark and Light side, as well.