Crossbowman

[Wladimir D]

If guided by interesting Koen Gh assumption that crossbowman lost his fingers due to trauma due to the string, then we can say that he was forcedly became a left-handed, since it is impossible to set the dart using only the thumb and little finger, but you can pull the trigger! 

Seriously though, I was shooting out sporting crossbow. To navigate quickly to a state to shooting, necessary beforehand to keep crossbow butt and the trigger, on (strong) hand. "Alien" (weak) hand is used as additional support and for overcharging. (The same is done at shooting from a Kalashnikov and pump gun.) The dart take in three fingers to 'weak' hands. In this case the thumb is directed into the crossbowman.  Feathering (stabilizer) of dart at the time of charging which is held in the hand, also directed towards the crossbowman.