I've seen that video a few times now. It's hard to tell because the camera is moving, but it sure doesn't look like muzzle flashes to me. I'm pretty sure it's a helicopter, but I think we're seeing the aircraft's lights distorted by the camera lens and the camera movement. I'm pretty sure this was taken by a phone camera.

In any event, it appears to be well out of the range of any door gunner, and I can't imagine a sniper firing from a helicopter (yes, I know they do it in the movies). But yeah, it looks weird.

Onward and upward,
airforce