Heard Gilchrist discuss this topic on the sports show on Sunday morning.
He mentioned that Steve Waugh was presented with almost exactly the same circumstances and appealed, apparently something then happened which delayed play for about half an hour, Waugh had a chance to reconsider his decision and then changed hi smind and called for the batter to return. Apparently said batsman went on to win the game for them.
Gilchrist said that he spoke with Collingwood since the game and he regretted his decision, he wished that he had half an hour to cool his emotions and think rationally about the incident. Gilchrist went on to say that some of his more experienced team mates should shoulder the responsibility because they were egging him on, they should have counselled him better.