As far as a single action revolver goes, i would never consider using one as a carry gun. I prefer "condition one", for lack of better term as my mil pro is striker fired, however i will take the safety off if i feel like i may be headed for a questionable situation, given the ability and time to do so.she still has a lot of take up in single action mode, full trigger coverage in holster, and a firing pin safety. There is just something i like about an external safety, as i have always included it in every practice presentation i have ever preformed, so it is second nature to disengage it. Would rather be as safe as possible.
A single action revolver carried on my side would be hammer down though, because it is not as time consuming to pull a hammer back as it is to connect hands to rack a slide. Condition two.
As far as the unfortunate fellow who shot himself in the leg, he should have never put any weapon, especially one with no manual safety, on his person minus a proper holster.