Most likely boiled the fluid at the same time as over heating your pads.
The Mspecs look more like a street pad, i use Project Mu Bspec pads for the street in my GTR and have had the odd spirited drive and never had them fade.
I have even used them on the track, i did over heat them on the track but in saying that the brake pedal never hit the floor i just noticed that braking power had decreased.
Would definitely recommend Bspecs for the street or step up th HC+ but that might be a tad over kill as they tend to be noisy and dusty.
The club racers are not suited for the street at all, i use these for track duties and are fantastic once at temperature