The wear indicator came on today and it's a puzzling one, pads and discs replaced all-around less than 6k ago, loads of meat on the pads that I can see. Is it at all likely one of the pads has worn on the inside side I can't see? I've no symptoms of a sticking caliper, sometimes I get a squeak when I reverse after the handbrake has been on, that's all. Is it unheard of for a sensor to break and give a false reading?