Customer told me my brake job sounded like a clogged drain

Had a lady bring her SUV in last Tuesday for a brake noise complaint. I did the pads and rotors, checked everything twice, standard $385 job. She picks it up and calls me 3 hours later saying it sounds like a clogged kitchen drain when she stops. I was ready to argue but drove it myself. Sure enough, there was this low groan I never caught on the lift. Turns out the caliper slide pins were bone dry and needed a full regrease, not just a quick wipe. Now I pull every slider pin and pack them properly on all four corners. Has anyone else had a customer describe a brake issue in a weird food or plumbing way that actually nailed the problem?