Ive heard that the passport system has "backdoors" that allow flagged passports to not trigger alarms. The terminals are querying a central location.

The bad passport holder is being escorted by a special/good passport holder.

When the special passport goes through the system, it disables alarms for, I dont know, say 3 more passports, then re-arms. This allows the feds to shuttle known bad actors through facilities without causing issues.

Its just a rumor I heard, dont know the veracity of the rumor.