The man said "when I brake." Now why would I not believe him?
Low tire pressure, bad brake hose, blah blah blah would pull all the time. Only real odd ball thing might be a rotor with soft spots on it. Doesn't happen often but does happen and will also catch when you brake.
Man said he replaced pads, not calipers or rotors. Didn't say anything about cleaning up the pins on the calipers or doing any sort of PM on them or even resurfacing/replacing the rotors.
To the OP rule out a dragging brake shoe. It's cheap and easy to do. If you don't want to buy a thermo gun then just use your palm on the center of the hub. Be careful not to burn yourself.
A dragging brake shoe is the most common cause of pulling when you brake. Hope this helps.