Lengkepan kalimah di handap ieu: McMahon meunang medali perunggu di 2002 FESPIC Games di 4 × 400 m relay, Lalaki's Javelin F37 di 2006 IPC Athletics World Championships jeung Lalaki's 4 × 100 m T35-38 di
2011 IPC Athletics World Championships. Dina taun 2006, McMahon narima panghargaan Achievement Award taun 2006. Dina Olimpiade Paralimpiade Beijing 2008, anjeunna réngsé kaopat dina Javelin F37/38 Lalaki.