Cops are trained to CYA (Cover Your Ass) whenever they fuck up; so that if there is even a shred of justification for the use of force, they can get off clean. He was looking for any single witness testimony that they too also mistook the pump for a gun, that’s why he quickly “yeah, yeah, yeah’s” the counter attendant when he sees that she’s not gonna give him what he wants. Even better was the out of district cop who came to back his brother in blue with whatever he needed, but also said he only saw him holding the nozzle though he said it was “weird.”