Has anyone been able to detect the presence of a primary light in that video? If he was just completing a cave dive when he ran across the guys doing the video I would expect him to have carried one, but I don't see one at any point in the video, either on or stowed.
I looked, did not see one. I even made the video lighter by 20 / 30 and 40% to try and view it better. I did not see any type of canister light, but that's not to say he did not have it stowed in his pockets... Oh wait, but you ain't got no pockets Lt. Dan.
I'll give him the benefit and say it was hidden on his person some where and not duct-taped to his helmet