I disagree.
Who’s to say this guy wasn’t testing the system, looking for vulnerabilities?
I find it incredible that he got away with it!
If there was an empty seat, he would have been on his way.
He simply took a photo of the other person’s QR Code on the ticket and boarded the plane with that on his phone.
A QR code for check-in is essentially a digital pass that contains all the necessary Information for your flight in a compact, encrypted format. This includes your flight number, departure time, gate number, and seating information, all encoded within a simple, scannable square.