I just invented something (in my head) that might help - what about sticking a paper-thin (0.008") force measurement gauge (
http://www.tekscan.com/load-measurement-system, B201-H, 1-1000lb) between the pad and the caliper and see what it says as you depress the brake pedal? If the brake pedal is moving but the gauge is not seeing more oomph, then there's a problem.