Kammala jumla mai zuwa: McMahon ya lashe lambar tagulla a Wasannin FESPIC na 2002 a cikin relay 4 × 400 m, Javelin F37 na maza a gasar zakarun duniya ta IPC ta 2006 da maza 4 × 100 m T35-38 a gasar
2011 IPC Gasar Wasanni ta Duniya. A shekara ta 2006, McMahon ya sami lambar yabo ta wasanni ta 2006. A Wasannin Paralympics na Beijing na 2008, ya gama na huɗu a cikin Javelin F37/38 na maza.