The guy was probably vaguely and weakly attempting to mock something Trump said. Trump's point, if I'm correct,would have been that supplies and people could not reach Puerto Rico by railroads and Interstate highways. Trains and ships both have large capacities, but trains are 2X or 3X the speed. Planes are much faster, but whether supplies come by plane or ship,those require air or sea ports to unload, trucks and truckers to transport the stuff, drivers, and clear roads.
DU-folk are so desperate for Maria to be Trump's Katrina moment - and disappointed that Harvey and Irma were not - that they want to believe relieving Puerto Rico should be slightly less quick and easy than a trip to Walmart.