Some states are easier than others. If they don't have a solid reason they likely aren't from new jersey. If they need a fake I'd they likely aren't mature enough to prep a believable backstory. If if is a fake I'd and they can tell a convincing back story theyve earned it.
But like....why even care as the shop owner? They provided an ID so you did your job. The risk of arguing with a babyfaced 25 year old from New Jersey on vacation seems overkill to 'protect' some 20 year old soldier who is home on leave with a fake ID from having a bud lite.