After reading extensively on the Subject over my life time ( I used to be an ASL junky), I know that mechanical break downs were for the German heavy tanks a bigger problem than the Allies. in fact most all the losses of German heavy tanks were from abandoment due to mechanical break down, If the tank was at the front and not able to be recovered, then It was destroyed by the crew.
If I were to engage in speculation , I would say more likely than not the AP shot "kills" were more likely on the Medieum tanks like the Panzer IV, and that the abandoned tanks were heavy's Panther's or Tiger's. To compiund this issue of abandoment All the tigers in the Bulge were the King Tigers save one( if memorie servies) This monster was very prone to break downs.
A prime example of how wacked the armor model is an event that hapened just a few minitues ago to me in the MA, ya I know not another storie... but bear with me...

I am in a M8 siting just behind the VH at a V base sofening up the VH with whats left of my 37mm HE.
A osty spawns, he drives around to whear I am so he can shoot me.
I wait, I got my trusty 50 cal UBER cannon in hand...no fear...take a drink....
He comes around the end of the VH and I T/O his turet with a 1 sec burst of 50 cal fire from about 50 yards( now that armore is 16mm thik and sloped at 25 Degreas....not to shure this is Possable in the real world)
I emideatly switch to his track, another one sec burst he is imobalized( even your vaunted expert on the killer 50 cal sya's that Panzer tracks could shrug off 50 cal fire)
Their he sits smoking and stuck in less than 3 seconds...But wait!
He is not one to give up easly, he jumps into his bow gun, and in just one short burst I lose my MA( the 50 cal).
I go back to my 37mm and continue on the hanger....
He respawns...
This time one shot from my 37mm to his turet t/o his gun, no suprise ost turet guns die easy.
Now I switch to his tracks, 5 hits in to his tracks and NOTHING he keeps coming firing his MG 34 the whole time, soon I lose a tire, then I explode...from a MG 34....lol