Are not all boarding passses scanned at time of boarding now. If the scanner used is not online to the backend database of the airline it raises questions around the security of the number and identity of passengers on board compared to passengers checked in on system. And hence the validity of the warning to immigration since passenger data now is preforwarded to receiving countries authorities. After all, the in the article alluded to airport security only checks that people have a boarding card or ticket somewhere for that day. Maybe they at the gate now just checks that passport name is like on boarding card, and the onboard count matches the boarded number from the gate, to improve ontime performance. Would be interesting to find out how often this happens on a company wide basis.