Not a failure at all, friend. Let me ask you this: if you were in a car accident and lost a leg, and then had children, would all of your children be born without a leg? Then why does one infer that all men after Adam would have one less rib? Use a little logic...it goes a long, long way.
Not that men really have to have one less rib, no. But think if they did, what a wonderful "confirmation" it would be. I mean, men don't have more and some people claim it anyway.