Jammed Clutch Pedal

We just replaced the clutch on a '98 Cav and although it seemingly went very nice and smoothly we managed to run into what appears to be a major issue. After re-assembling everything I went into the vehicle to depress the clutch pedal to start the bleeding process. The pedal was jammed at the top with little to no movement allowed. I exerted more pressure and with a heart breaking "bang" the piece at the firewall that holds the push rod broke and the pedal went to the floor. I'll have to replace this piece but I have no idea why the pedal jammed in the first place. Does anyone have any ideas as to what might have happened?