Possible Clues:

• Gunners having first approached, react fearfully — not wanting to get shot
• Unlikely to be framed?
• Averse to being filmed
• Out of the picture, say
• One of those not in the picture is accused of this? Not wanting to be shot!
• Afraid of getting shot
• Preferring not to be put in the picture
• Having turned up imprudently, left out, not wanting to be shot
• Afraid of the lens
• Resisting being taken?