If you held a soldering iron for 3 mins on the shaft it should be a lot more than "slightly hot." Glad you got it off though. I've had that happen on a CC 2200kv motor more than once. First time I cut off the pinion with a reinforced blade and high speed dremel. Second time I used a pair of dykes as a level to pull it off. And I didn't use thread loc on either one.