It looks like the lion was fenced in, so it might've been some hunting club or some crap like that. Still doesn't make it any better.
Like someone above said, if the lion attacked a human it was probably out of self defense. You can't ask the animal not to defend its turf. That would be like asking you not to defend your house. If the lion came near your house, fine ... you'd be defending your ground. If you gonna eat that lion after you killed it, fine. I have 0 respect for the people on the tape regardless of the legality of what they've done, unless that was dinner.