That's basically the FAA's Ace up the sleeve. My company has another one, hidden away in the GMM is the statement "Company work cards, combined with manufacturers manuals are the complete instructions for aircraft maintenance" Just one example: Lubrication work cards just say to lubricate, and have a diagram of all the lube points, like maybe 100 points in a DC-10 leading edge. The maintenance manual instructs to wipe fittings clean before and after lubrication. Almost no one does that. You say something to them and you're a dick because to them it's no big deal and a pain in the ass. They don't consider that the grease attracts abrasives, and that they may inject them into the lube point. Back to the ace up the sleeve. If the mechanics get the job done quicker, that's great. If it's determined that premature wear was caused by the lubrication deficiency, it will fall back on the mechanics.