As is effusively discussed and debated in the blogosphere and elsewhere, the Sydney test match will be remembered for all the wrong reasons. The causes for this state are four-fold: one, pathetic umpiring (See the Youtube Video on this); two, alleged racist remarks; three, sledging; four, poor sportsmanship.
No doubt, the standards of umpiring should not have stooped so far. If there are stringent behavioural requirements on the players, why not have a more strict guidelines for the officials as well. True, to err is human, but to err consistently is insane. This poor umpiring might be the reason for the other three to go beyond control.
Racist remarks and sledging are tightly coupled. What is racist to one may not be so for the other. Who is to define in which context (Indian/Australian) the remark is to be interpreted? "Tere Maa ki..." can be a not-so-abnormal remark in Punjabi, Monkey could be a racist remark to Symonds, but whatever it is, it depends on the acceptability of sledging as a concept in the game. I personally feel sledging inevitably happens in one form or the other whenever you play a game. So it may be difficult to drive out sledging from Cricket also. If sledging has to be accepted, it is difficult to regulate what is exchanged.
After all, there is always a human element to everything. If Ponting or Symonds reiterated to Kumble that Monkey is a very offensive remark (!), instead of going to the umpires and the (super-judge) Procter, things could have been dramatically different. The lack of sportsmanship allegation might not have come up at all, all the ill-feelings would have been restricted to India-Umpires in the place of aggravating to an India-Australia conflict.