They're working as baggage handlers, so that's a safe bet.
All joking aside, I think it’s quite rude and elitist to imply something about someone’s intelligence just because of their chosen occupation. My dad had a Master’s in electrical engineering, brilliant at maths and physics, and was top of his class at university. As an immigrant he could only find jobs doing manual labor and whatnot.
I didn't say it was a certainty, just a good bet. Besides working as baggage handlers, engaging extraordinarily risky behavior and then directly taking actions that led to being caught does not speak well to their decision-making capabilities.