they got a point actually.....
It's not that the simple physics of force applied to the middle of a thin object will either bend it or break it eventually. That one's easy and obvious, and anyone sitting down on a thin, expensive, slab of metal and glass in his/her back pocket should receive no pity, imnsho.
The thing is , from observation of a lot of Youf in skinnies + mobile phone mangling this actually rarely happens. The phone comes Out before the behind is parked on whatever surface is used for reposing, so is rarely ever sat on.
While in Attenborough mode I did notice that the majority of cracked screens had their telltale lines along the diagonal of the screen, indicating that the force applied was a twisting force along the long axis of the phone, not the straight-up downforce used in the test. This is what you get while bending forward or squatting down in not-even-so-tight jeans where the force of the rolling action of the gluteus maximus, backed by the hinge of the hip joint ( plus the mass of any tight-packed adipose tissue ) is applied to anything present in the back pocket.
anecdotal as it is, I do believe Sammie has a point in stating the performed tests are less that useful, given the observed results in the wild. I doubt that they would want to test this though, given that a thin phone can take even less twisting force before giving in, and the results may show that the force required falls well within the realms of Normal Use, giving rise to another kind of embarassment..