Look, Alec, I get that you're absolutely gutted by this.
I could be convinced that you legitimately believe that you did not pull the trigger. Our brains... our egos... will tell us some amazing lies in order to protect our id. Even though I think you're a huge asshole, on some basic human to human level, I feel bad for you, because this is obviously a horrible experience.
But guns, and most specifically Colt Single Action Armies and their clones, do not work that way.
If it were some striker-fired semiauto, we could concoct some bizarre and cosmically unlikely hypothetical whereby the sear broke at the same time as the aliens from planet Zoltar beamed the firing pin safety out of the gun, but not on that smokewagon you were holding. You had to at least manually cock the hammer on that replica hogleg while pointing it at someone.
.