As Musk points out, this is the fastest pump they could find in their area. Pumps vary tremendously in speed. Actually I'm curious about why the same pumps are sometimes fast, and sometimes very slow. Anybody know? Does tank level really matter that much?
I think it has to do with how much fuel is in the gas stations storage tanks. When the tanks get low they pump more slowly. I think it has to do with the pressure created by the weight of fuel pushing gas out of the bottom of the tank faster, there is more potential energy to push the gas faster in a full tank, mass x gravity x height equals potential energy.
In the US, fuel pumps meant for regular sized cars (not trucks, boats, planes, etc) are limited to 10 gallons/minute. If that pump really was that fast, then it really was (among) the fastest legal pump(s) in the area.