I just love this interweb thingy! it is so fast and easy to find out all sorts of useless facts!
SPOILER ALERT! If you still want to guess what the "error" sport was, don't read on.......
"Australian Rules Football was a demonstration sport in the Brisbane Commonwealth Games in 1982.
An exhibition game between the premiers of 1982 (Carlton and Richmond) was held at the Gabba as an official Demonstration sport of the XII Commonwealth Games. The ground was a sell out and patrons saw Richmond reverse the grand final result by defeating the Blues by 18 points, Richmond 28.16.184 defeated Carlton 26.10.166."
From
http://www.blueseum.org/tiki-index....alth%20Games