ABS light is on

Recently, my friend had engaged the emergency brake, and instead of using the lever to disengage, he pushed the brake further down, until it gave way, leaving the pedal wobbly and the brake light on. After pulling the lever and moving the pedal manually, the parking brake light is no longer on, yet the ABS light is lit, and the parking brake pedal, when pushed down, extends further than it should and does not seem to quite "lock" in place. However, the light does go on when the pedal is pressed. Can I assume he snapped or frayed the cable? And how much is a reasonable fee for this repair? Thank you!