It very simple. They just need to have the clientelle flash them anything that looks legit. If the paper is phony, they can rightly claim their door people/hostesses are not forensic document examiners.
I guess there are times when organized lying is justified.
Especially so, when the rules are arbitrary, contrary and just plain stupid. We are moving into a Speak-easy mentality, where natural human behavior is ignored by policymakers.