The worst I've encountered of this type of head-in-the-sand logic was in NZ. They have a law that if a person buys alcohol with companions, the clerk will check the IDs of all of them, not just the buyer's. Presumably this is to stop underage kids having an older friend buy them booze. In reality obviously, teens without IDs just wait outside and literally 100% of the times this law is applied is when an over-age-but-without-ID is accompanying someone shopping for some dinner wine. Like me and my ex gf...