Weights and Measures(or equivalent depending on where you are) handle the accuracy of the pump. I do not believe that they would handle issues of gas leaking on the ground. These agencies want to guarantee what the pump says is what is being pumped to avoid fraud. There is no reason a gas station would intentionally short a customer by having gas go on the ground, because it is gone and they can't sell it to someone else.
Now, as to the report. It is a bit hard to figure why it took almost $45 worth of gas before you realized that "most" of it was going on the ground. The only way I can see this happening is if you were not watching the pump. Which by the way every gas station I am aware of says to NEVER leave the pump unattended.
Not knowing the exact cost of the gas, but according to AAA the current averge price in Texas is about $2.50, but even at $3 a gallon you would have pumped 15 Gallons before you noticed it. Had you only pumped one or two gallons you would probably have had a much better case.