There was the man crouching against the corner of the house, looking like he could possibly have an RPG to blow the shooter out of the sky.
The helicopter was at very long range; no one of the guys on the ground looked at it. The "RPG" was pointed to the ground. You can see that it was a camera before he starts to fire. Further, an RPG takes two seconds or so to draw, time which the gunner could've used for confirmation. It didn't look as a threat to the helicopter, once seen; still the gunner freaked out and shot them.
Very organized team? They were two guys in a dirty van.
Yes, it wasn't, strictly speaking, murder. Still, it was unjustified, criminal use of force.