Neekoy, over the course of the series we've all had some bad decisions. What about when Pietersen was given out caught behind after the ball had hit a few body parts, none of which were bat or glove, or when shortly after Bell then was given out caught behind when he hadn't got anything on it? Even in this test, though Strauss was actually out there was an inproper use of the third umpire. The third umpire can only be used to see if there was contact if the umpire is completely unsighted, which he was not, so he would have had to give the decision without the aid of the replay, meaning that he should have given the benefit of the doubt to the batsmen, meaning Australia don't look like getting a wicket, meaning Flintoff never even has to come into bat.
It's always been thus in cricket. There will always be bad decisions, but they usually do equal themselves out over the course of a series, if not simply over the course of the match.