Realistically, the reason for the beating is probably that the thugs felt "disrespected" by the guy for whatever reason.
My bad, Papa. Yes, you’re right.
Years before 9-11 young thugs were tailing people out of rental car agencies at BWI airport for the purposes of staging a stick-up. The reason was simply that they knew the chances of getting a gun shoved in their face was just about as close to zero as you could reasonably expect.
BTW, they’d create a fender-bender situation before the expressways to get you out of the car, then relieve you of your possessions. Then they were gone up the next on-ramp.
Of course, THEY were armed!