Here’s a novel thought...
DON’T VALET WHEN YOU’RE PACKING!!!!!!!
In crystal clear hindsight —
If he knew the valet saw the gun, immediately get back in the car and drive for the nearest state border.
Well, maybe. Drones know no borders. (Nor do JBT/SWAT in full pursuit.)
That goes without saying. You should never valet your car under any circumstances, unless you don't mind getting your car back with dents, scratches, and many more miles on it than when you relinquished it. This especially applies if your car is fast and expensive, such as a Corvette, Porsche, or the like.