It's very possible that he can, by applying uneven force to certain weak points - supposedly by the volume button as the video and Cult of Mac have proven. Consumer's test applied even force and did not mimic somebody sitting with his iPhone in his front or rear pocket. The ease that backwards cap boy bent the iPhone is telling and better mimics the random nature of somebody sitting and bending it at the sweet spot.
And we will see exactly how possible it is in the upcoming weeks by the number of returned phones due to bending. Of course it's possible, I just don't think it's likely to happen.