Shawn,

In an effort to make a complex problem simple, remember that any mechanical system can fail at some time. To isolate the frame mounted pin as the demon here is not quite fair, since it is just a one of several links in the chain. A failure could come from the ammo; primer, powder, bullet, case, loading or reloading methods. A failure could come from the trigger mechanism, springs, lubricant, dust or dirt. A failure could come from the hammer system itself; hammer, mainspring tension, rebound springs, block, screws, pins etc...or, under stress, the failure can come from the shooter.

Believe it or not, the shooter's action can cause the gun not to fire. I have seen a shooter "short stroke" a trigger and miss a shot and later claim it was the gun that failed. Like a number of other "High Emotion" posts on this forum, people can report on just about anything they want, without having the proof to prove it.

In order to put your mind at rest, I suggest you perform a "Design and Failure Mode Effects Analysis". This will give you a better understanding of the variables in the system and the reliability expectations you may encounter.