Howard, as a multi-department instructor perhaps you can confirm whether this was true....Apparently some departments forbid their Officers to carry S&W's with the 'safe' on; and were instructed that decocking was always a two-step motion requiring the safety off when decocked. With the pistol in DA mode, there was NO reason to have the redundancy of a safety. Thus drawing and firing would be same whether S&W, Glock or other Traditional DA pistol. ??
Different departments adopted different policies regarding how their officers were to carry specific firearms. When the traditional S&W semi-autos were in widespread use among Law Enforcement personnel, there was a measure of debate concerning how those pistols should be carried. One camp believed the pistols should be carried with the safety in the "safe" position. Their thinking was: 1) an officer had to consciously disengage the safety before firing, so accidental/unintentional discharges were less likely. 2) If a suspect managed to disarm an officer, he/she would be unable to immediately fire the pistol, thereby giving the officer an opportunity to react. The other side held that the double action trigger provided the same measure of safety as a double action revolver and carrying the pistol with the safety engaged was an unnecessary redundancy that required an officer to take more time to react during a life-threatening incident.
This was one of those Law Enforcement debates where "never the twains would meet." To this day, you still see some manufacturers offer firearms with and without a manual safety so as to accommodate people on both sides of the isle. Personally, I was (and still am) in the safety-off camp. I de-cock the pistol and then reflexively disengage the safety before holstering the pistol.
Howard