elwaine - If you mean evidence, as in photo's of damaged/failed parts, or an agency report, detailing the event, no, I'm not aware of the existance of either of those. I guarantee we'll not see any such evidence, or an admission by Saf-T Hammer on the issue. When NC DOC's problems with their M-64 revolvers occured last year, (and made the national newspapers) Saf-T Hammer denied any problems with locks, and any other "feature". I'm unaware of any change in their position.
I've read the threads supplied above, and talked to other shooters. My opinions on the internal locks, are based on my experience. The experiences of others may lead them to other conclusions. If anyone took mechanical engineering in school, they will remember the basic tennants of adding parts (complexity) to simple mechanical devices, reliability decreases. I spend considerable money making sure my handguns are reliable. I've no need for any handgun that isn't. The inclusion of the unnecessary internal lock, and it's extra parts, in a handgun, disqualifies it as carry gun, for me. YMMV.
If one uses their revolvers, or pistols for that matter, as paper punching or competition game guns, the internal lock is probably of little consequence. If the IL fails and your gun locks up, you've lost time/points, wasted a trip and been annoyed, better luck next time.
For those of us that carry handguns for self defense, or as part of their employment, it's an altogether different matter. The stakes are much higher. I would never recommend an internal lock equipped handgun, as a carry piece. Sure, all handguns can fail, from any myriad of things, and probably will yada yada yada. Well, that may be true, but in my case, I can guarantee that the failure will not be from an internal lock. Again YMMV.
Oh, and yes I've personally seen, first hand, a Saf-T Hammer revolver lock up. It was a model 329, 44. It's first trip to the range, fired three shots, and locked up. The flag next to the hammer, was slightly raised, the hammer was partially back, the cylinder could not be opened. The owner (a lawyer in the court house who knew me, and shoots at my range) was shooting it in the lane next to me, and asked for assistance. We (RO and I) tied a rag between the hammer and frame, took the side plate off, and disasembled the revolver, to get the remaining 3 rounds out. The owner sent it back to S&W under warranty. It returned with a paper, showing the work performed. It simply said, "replaced spring, returned to spec". He promptly traded it at the next gunshow for a pre lock 629. Regards 18DAI.