He basically did a test where he bends the phone to check the bend-ability of it. The titanium frame survived, but because the middle portion of the phone was weaker, the glass bent and broke anyway.
It isn’t exactly a non-issue, because situations like this can and will happen. It was however, blown out of proportion, because it was testing an extremely niche situation.
I do feel that he has a point though. Although he failed to properly test what he intended to show, it does show a weakness in the design. A phone rarely experiences such a uniform force when it’s dropped/ sat on.