So the problem didn't start with the carpet wedged against the gas pedal?

There is quite a bit of pedal return resistance on mine, and doubt a carpet, even a heavy rubber mat could hold mine.

Did I understand you to say the cable is not binding, that it is the mechanical linkage? I know it connects to the cruise with a couple of short rods with ball sockets before connecting the IP, and I could see those rods possibly getting fouled up. Hope you find out fast, so this doesn't happen again and thanks for the heads up.