Define "lucky"

A heartwarming ‘Forces’ story from the Sun:

Luke, a 22-year-old lance corporal, was on patrol in Nad-e-Ali in Helmand when an insurgent’s bullet hit his body armour and ricocheted into his face.It tore into his cheek, broke his jaw and came out through his mouth.

Mum Kim, of Torquay, Devon said: “He knows he’s very lucky but he’s trying to play down his injury.”