Your description indicates that the parachute (cup) seals inside of the master cylinder are bypassing, which means no pedal pressure at all. In the early stages of failure it works for a while then doesn't. When you pumped the brakes did you push in or did you kick it, hammering the brakes usually makes the seal flare and grab when just pushing in on the pedal won't do anything, but this doesn't always work. As long as the rear seal is intact the master cylinder will not leak out of the back.

And yes i have had this happen to me before, it really wakes you up doesn't it. Now i can't say for sure that the ABS is not the culprit but i don't think it is. Normally when the ABS faults you still have pedal pressure and brakes just no ABS. If i remember correctly the ABS on your car should just limit the pressure going to the wheels, if it really acts up the car won't stop well but you will still have pedal pressure but this is very rare. HTH