MLH/BZL/EAP is fun because you kinda keep going back and forth across borders a few times as you walk around, and depending on where you "come from" the destination country can have slightly different requirements for entering upon arrival (which is checked at the gate on departure, I did get a random customs check on arrival once when crossing the swiss/french border). Not a problem on the happy path but could get hairy if you get into trouble I guess.
I think in France it may depend on "plan Vigipirate" levels as well.
What I do not understand, what is creative here? If he had a buddy pass, and was denied because of a full plane, how could he hope for an empty seat? That sounds super dumb?
2nd I don't understand: The scanning at the gate doesn't check for tickets scanned twice? It marks people off, not? I thought that is how they call sometimes missing people out? So why were there no problems when he or the real owner scanned the ticket a second time?
2 - a person boarding after him was "denied" because her passport had already been scanned but they let her board anyway.
It's in the video embedded in the article.