They obviously GUESSED wrong on your behalf. The pump can be tested one of two ways, with a pressure guage to see if the pressure and / or volume of fuel being delivered are adequate or not. The other test is a bullet proof test for pump electrical integrity that can actually show you the commutator humps on the pump and see how many amps the pump is actually drawing, and what the RPM's of the pump are. Normally about 6K. A low amps probe and a lab scope are required for ths advanced testing procedure. See PICs of waveforms.
Thanks for your question,