[emeraldd]

Looking at the full picture, that rifle is very likely not even pointed at the man being given water. I wouldn't be surprised to find that the solder with the weapon is facing away from the whole scene, and not watching the two helping the man on the ground at all.

[russh]

I think it only looks like the rifle is pointed at the man because it was taken with a telephoto lens that compresses the depth of the image a lot.

[joncrane]

The fact that the drink-giver's fingers are on the subject's head gives it away. No way his squad mate is pointing his gun anywhere near his colleague's fingers.