Ruined 9XL Motor?

The other night i was at the track running my big crt hard, had been for about 20-minutes, when my negative motor wire came off of my mamba max control board and needless to say, it came to a complete stop and wouldn't go anymore. I was near full throttle down the backstretch when it happened. Afterwards, the truck would not roll freely, so i thought it was the diff, took the pinion gear off the motor and the truck rolls fine, but the motor shaft will no longer turn by hand, did i fry the motor?