Mezue ahịrịokwu na-esonụ: McMahon meriri ọla nchara na 2002 FESPIC Games na 4 × 400 m relay, Men's Javelin F37 na 2006 IPC Athletics World Championships na Men's 4 × 100 m T35-38 na
2011 IPC Athletics World Championships. N'afọ 2006, McMahon natara 2006 Sports Achievement Award. Na 2008 Beijing Paralympics, ọ gbara nke anọ na Men's Javelin F37/38.