what really surprised me was that the incident that triggered the ball was incidental contact. essendon took exception to chance bateman legitimately going for a mark and taking out winderlich as he did. bateman played hard+fair football for one of the rare occasions in 2004 and essendon retaliated too it, starting the brawl.
I thought it started by Bateman having another crack at him as he went off the ground with blood.