I think its a flash of a bullet coming out of a gun. The way Alex is standing doesn't look the way someone would be standing with a torch/ flash light. Plus the hand motion is weird you don't hold a torch at chest height where with a gun you do because your aiming higher up.
I think that the original image from the books is a gun shot. The flsh from a gun.
The image of AP on the red is clearly a torch, fair enough.
The one on teh url posted could be either.
Personally, when i go using a torch, which, to be honest, i don't very often, i hold it at waist level.