I'm not sure we're talking about the same 'lower right corner'. I held it up by the right corner near where the trackpad is, not near the hinge. Maybe it is due to some wear or maybe it wasn't the entire chassis flexing, but there was definitely some give there in the materials. Also, of course, the MBA screen wasn't closed either, so I literally held it from the thinnest possible corner.
Of course, I never lift up any of my laptops like that, but then, none of my laptops are that light either, so never had the urge to.