I've heard of people accidentally hitting the mag release on semiautos. I've NEVER heard one accidentally hitting the cylinder release on S&W or Taurus revolvers. I'm sure there's an exception to each and every rule, but that's not an issue that a statistical significant number of S&W owners worry about IMHO.
As far as the cylinder unlocking it's under recoil, that simply sounds like a poor design and not a push vs pull issue.
Having seen some photos and other images of the older ways of how one “should” hold a revolver, the orientation of the Colt cylinder release actually does make sense. I have seen the checkering on some of those older Colt DA revolvers. Plus, I do remember reading at least one older book actually telling the reader to place the thumb on the cylinder latch.
Then, there is the single-action shootin’ crowd, who are still being instructed to place their right thumb on the recoil shield, by at least some instructors. Notice that this instructor’s thumb has worn the finish thin, where is right thumb is positioned, while shooting:
World Champion cowboy action shooter Jim Finch, a.k.a. "Long Hunter" offers tips and advice about cowboy action shooting in this excerpt from the DVD, "One o...
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So, let’s picture a shooter who learned to shoot with Colt’s Single-Action design(s), or the earliest of the DA revolvers, which did not have swing-out cylinders, and wants to move-it-on-up to the newfangled revolving pistols with swing-out cylinders. Yes, the Colt DA revolvers’ cylinder latch does make sense.
Then, there are those of us who shoot revolvers, from time to time, with our “wrong” hands.
A lefty reload can start with the left trigger finger moving to that latch, as the right hand moves toward the cylinder, from the right side of the frame.
Of course, anyone whose thumb gets too near a S&W cylinder latch, of the type seen on the 70s/80s/90s revolvers, after the flat latch but before the modern latch, will get a harsh lesson in the effects of checkered metal on bare skin, if shooting Magnums.