You're thinking in the wrong direction - if you'd live in such society you'd understand that you're not trying to prove a negative ("you're from the wrong case"

You're thinking in the wrong direction - if you'd live in such society you'd understand that you're not trying to prove a negative ("you're from the wrong case"), but you need to prove a positive ("you're from the right circles, someone the boss knows knows you"). It's like getting in to american closed society - they'll check your social ties and if noone can vouch for you or know you, you're immediately suspect. And those checks aren't made in your face - it's usually in the background and async.