Reliability of the weapon is not the primary argument for preference of a revolver over an automatic. The issue comes in the case of a close in engagement, where most uses of a concealed weapon would be. If an attacker is able to grab the weapon, there is a significant chance that the upper receiver can come out of battery and render the weapon useless until released. A revolver does not have that problem and would still be able to fire (especially a ‘hammerless’ variant) if grabbed.
I personally have seen surveillance videos of automatics failing to fire during violent encounters and have had them do so to me on the firing line during qualifications.
A revolver most certainly does have this problem and in most cases it's actually worse than an auto. It's very easy to grab a revolver and prevent the cylinder from rotating thus preventing it from firing. Another way is to get the tip of a finger behind the trigger of a DA revolver and it can't be fired. Both designs have their weaknesses if someone can get their hands on the weapon.
Grab the cylinder on a DAO and see if you can pull the trigger.