 McMahon played 18 games in 2003 and established himself as an important member of the Bulldogs' defense, being assigned dangerous small forwards and providing run and rebound.After seven seasons and 114 games for the Bulldogs McMahon was traded to Richmond for pick number 19 in the 2007 Draft.Richmond coach Terry Wallace, his original coach at the Bulldogs, lured him to Richmond, keen to exploit his pace and kicking skill.