Capped and hammer eased down on the cap. Really and truthfully all of these questions are easily answered by common sense. I get a kick out of most people honestly believing that in the 1870s and 80s people walked around with their Colt SAA loaded with 5 rounds and the hammer down on an empty chamber.
Im curious of your information source saying it was common or universal to carry the SAAs fully loaded, as Ive seen a fair amount of information stating they commonly did carry them with 5 rds.
One book* in particular mentioned that when the SAA came out, people were carrying them fully loaded and the hammer in the "safe" notch, but that there were a number of known instances of people having them discharge when something hit the hammer spur or the gun was dropped, the source seems to indicate that the percussion guns were carried fully loaded, and with the hammer between the chambers on the pins that were provided on the Colts, and generally without incident. The unintended discharges, and some ending up shot in the leg as a result started the habit of generally carrying with 5 rds. This was said to be in the mid 1870s after the SAAs started showing up in more numbers for civilian sales (first year or twos production mainly went to military contracts). Wyatt Earp also mentions it in written piece, I believe associated with sales of the Savage pistols in the 1920s, as well as other writers in the early 1900s mentioning it as the old habit, Elmer Keith being another writer mentioning it in the 1930s as being told him by older men that it had long been the common method of carry.
I commonly fully load my Colts type percussion revolvers and have never had one turn to a live chamber when holster carried, though I did have
several instances of Colt SAAs carried with the firing pin down between the rims of 44 spl and 45 Colt shells turning and the pin resting on a live primer before I decided I wasnt quite as clever as I thought. One of the holsters I used was a snug fitting half flap that entirely precluded anything snagging the hammer to allow the cylinder to turn.
*The book mentioned may be either
Firearms of the American West Vol II by Garavaglia and Worman, or
Guns of the American West by Joseph Rosa. Both books relying/quoting heavily on period writings and information. Both have excellent information on a variety of old arms and their use at the time.