My take on the whole affair, is that there is a great number of bodies that have fallen when a cap and ball pistol/revolver has spoke its piece. Whether those bodies be Native Americans, soldiers, settlers, bandits, rustlers, gamblers, and the list goes on, they are still dead and buried. Are cap and ball pistols/revolvers perfect? No, but they can still get the job done.
Take drills for instance. First, man used a wooden shaft tipped with stone or bone, and worked it between his palms to make a hole. Then, some got the idea to use a bow to work the shaft. Others thought to use a weighted whorl to get the job done, then water wheels, steam, electricity, and now rechargeable batteries. Thing is, all of these devices still drill a hole. But, if any of these devices are left to neglect, or the user is unfamiliar with its use, then of course they will fail.
What makes a cap and ball pistol/revolver reliable is attention to detail. The details in its function, its loading, its care and its use. Hickok understood that and saw to it. What got him in the end, was not a misfire, just pre-occupation with his cards.
Just my two pence.
CP