When he made reference to 'popping a cap', I would have made sure my hand was on my protection and ready for the worst. It only takes seconds for bad things to come from situations like this. One more reason to carry something small enough to fit in your front pocket. one hand on the gun and the other pumping gas.
Not to be critical, but I might have considered going elsewhere for my gas while he filled up. Just my 2cents though.
