[Hectic]

It was going to happen regardless of the torque motor or not. Is the gun brand new? Was it opened by you or someone else in the past? Either way the most likely cause is bad shimming a high torque motor wont just sheer off teeth. Failer due to a high torque build will most often be due to the heavy spring so either the piston will sheer teeth or if its a full metal rack it may sheer teeth off of the half gear part of the sector gear. Or the pinion can stripp if it just cant pull the spring.
But for sure the high torque motor isnt the cause of the stripped gears especially in that location.
Going high speed will sometimes strip stuff but most often the piston.
Shimming was for sure the culprit and or the bushings could be loose causing the gears to wobble a bit giving the same sort of shmptom as bad shimming.