The thing is, does one moment really prove anything? Alex Smith had an adversity moment against the Saints, but that classic comeback didn't really impact him going forward in the offs or in rest of career.
I agree with
@Jmare007 about the rest. I don't think anyone says we're unbeatable. It's football. Things can happen. It's pointless to both think we're unbeatable or just being straight scared of anyone because Brock is unproven/due and D has weak spots.
Shiiit FWIW we saw Buffalo and Cincy having issues putting teams away against a second and third string qbs, at home.