I don't vouch for all this, but FWIW:
In the days of break top revolvers, there seems to have been a lot of concern that in close quarters combat an enemy could grab the top latch and open the gun, thus unloading it and rendering it harmless. Gen. Schofield apparently was so concerned about "latch snatching" that he redesigned the latch and got S&W to make modified guns called the "Schofield Model". He also had enough influence with the Army to get them to adopt the gun for use alongside the Colt Model 1873, and to make a common cartridge.
Then S&W became concerned once again about those nefarious latch snatchers, this time sneaky bad guys who supposedly grabbed police revolvers. The result was the Perfected, which had both a top latch and the new type push release. The user had to operate both together to open the gun, thus frustrating that nasty latch grabber.
Some folks are under the impression that the Perfected was a prelude to the swing cylinder hand ejectors and that the lower latch was adapted from the Perfected. In fact, the Perfected did not come out until 1909, seven years after the Model 1902 HE, which was the first gun to use that push button.
It seems more likely that the Perfected was something of a last gasp attempt by S&W to give the top break a few more years of life, though ultimately some stayed in the line into the late 1930's. But not the Perfected; it lasted only until 1920, with some 59,400 made. It is a highly desireable collector's item today.