Possible Clues:

• Onset of pain in the kidneys set back marksman
• Gunman after wildfowl, right?
• He could shoot back about the points they have
• One firing from cover
• Marksman frets about having lost sixth place
• He shoots from a hidden position
• Sharp-shooter
• One aiming for second child half-heartedly
• Marksman who fires at bird (rook)
• He shoots from hiding-place