It's a "monkey see, monkey do" kind of situation. The guys that did the video pushed the boundaries of what is safe to their extreme and beyond, but they lived and did post the video of them successfully doing it. If they are certified divers, knowing the physiology of diving, and still did what they did, then there are others out there just like them watching and thinking "They did it, I can do that too!"
No, a disclaimer will not stop others from doing the same if they have set their mind to it, but maybe a disclaimer MIGHT make another person think twice before copying them. I do not see a disclaimer as a "get out of jail free" card, but as a warning that the actions are not safe and should not be attempted. Of course, these guys were stupid enough to do it in the first place, so they are not going to warn others not to do it, and they posted the video for all the world to see how proud they are for doing it. This where my irritation at them comes from.