Lonewolf
The problem is that this passenger could be a clever, lying piece of s...t, trained on MS Flight Simulator, looking for an adrenalin kick, 15 minutes of fame and a story to lighten up his miserable life.
In best case.
He could also have been suicidal poor bastard, with revoked license longing to end his life in an epic pilotīs way, or why not high as a kite from sniffing cocaine as dessert, and eager as hell to show how to master a 744.
Or whatever else you can come up with.