Your goal is to get the most out of your first shot. "You can't miss fast enough" Ray Chapman. Most double action triggers SUCK! The reach is too long, combined with the long heavy pull and often a grip that is less than perfect you "drop" the most important shot. There is a reason the HiPower and the 1911 have held on so long, I hope you understand better now.
Believe it or not, most cops won't have to draw and fire in a split-second confrontation throughout their career. Showdowns, ala "Gunsmoke" are not that common. They'll probably have to struggle more often to keep a gun in the holster than to get it out quickly. That's why they're issued retention holsters and not given single-action weapons.
I think you have confused gun competition with the real world. At this year's IDPA Championship, the fastest/lowest times were shot by a competitor shooting a Glock.
(There were 90+ Glocks in the competition, I think, by far the most common gun. There were 44 Glock 34s! These are pretty serious competitors using guns that arguably could be carried for self defense. There weren't many BHPs, if I remember correctly. Only three SIGs. What does that say about SPEED and the importance of first shots?)
Faster? Only if you've praticed a lot. Most cops (and most people) don't practice that much. (I personally know of exceptions -- a couple of which are VERY proficient.) For most cops, however, a DAO gun is probably faster and better. Or an almost-DAO only, like a Glock. I have a DAO Sphinx and its faster; I just haven't shot it enough, yet.
And I would argue that the Glock's trigger is BETTER,
relatively speaking, than an unmodified BHP, given the mag safety which makes for a ugly trigger.
I'd take a tuned BHP any day, but thats not an option for most cops. Police departments are NOT going to modify triggers or remove mag safeties. (I suspect it will be a cold day in hell before you see a police department in the US issue BHPs or other similar single action guns to anyone but a special weapons team -- and probably not then; they'll go for something in a larger calibre or larger capacity.)
Then, too, the BHP, requires releasing the safety first... and DAO and Glocks don't. If you don't practice a lot, that safety may be your undoing.
I'll agree that Glocks aren't as ergonomic as a BHP, but I consistently shoot one (a Glock 34) just a hair faster (with the same accuracy) than I do most other guns, even though I like the other guns better.
What's that old saying? Oh, yeah: "nothing succeeds like success."
ower, Speed, and Accuracy (DVC). Some guns just handle better than others. The Single action trigger also helps speed. The better ergonomics promotes both speed and accuracy at the same time. 
