Watched a YouTube video last year where a mechanic tested a bunch of torque wrenches against a calibration rig and half of them were off by 15 percent or more right out of the box. Even the pricey ones can drift if you drop them once or store them set to a high number. That Tulsa guy probably saved you a lot of grief, busted knuckle and all. I check mine every few months now, takes five minutes and saves the guesswork.