Um, you, and everyone else who ridicule the guy fail to see beyond the lads daft hat and actually watch and see what happens.
The important bit isn't the end of the video where the phone has bent as much as he can make it. The important bit is when he starts. It doesn't really take much effort to get the damn thing to bend. That's the point here. Once it deforms even a little bit, the test is as good as done. Tying it in a knot afterwards is irrelevant.
The users here with the issue have all said they were not aware of any undue force used.
The scientific process is immune to ridicule, and is repeatable. That was my point of the parenthetical comments made at the bottom of the post, which I assume you are reflecting on.
As for why it bent, I'll give you that, and use it as anecdotal evidence that putting the phone in your pants pockets is a bad idea. I'm amazed at people that walk around with phones in their back pockets that are amazed that when they sit down, force is exerted on their phones. This is more in the statistical realm, and there is debate on whether that is indeed science at all, where statistics are what "might happen," and hard science is what "will happen." The counter to that argument is no one can know all of the factors that go into a scientific law, so those things have to be accounted for, and there you go.
"I was sitting on the non-glass side!"