Something that you seem not to be considering there, alex_d, is that the case is actually a pretty solid metal construction, so the force of doing what Bob described is dispersed through the metal to the flat surface (the display isn't pinched between them at the edges, you see), rather than being placed on the display.
What Bob has described was the suggested cover installation method that the Sony folks gave us directly (it was one of the very first things they told us, in fact, so they apparently felt it was important

) at the
Blogger's Day last year. I believe I'll stick to it, and suggest that others do the same.