I may be a bit paranoid, but if an unfired round that I pick up at the range looks like it might possibly be a reload, I pull it down for components. This has given me a fair amount of experience in decapping live primers. The first few times I did it, I took all precautions, gloves, long sleeves, face plate etc. After pulling many hundreds (possibly thousands), with nary a pop I changed my technique to what an EOD friend called the "Modified Half A--ed Method" that he used for crimping detonators. He was trained to always hold the crimping tool and cap directly behind the largest set of muscles that he (or any other human) possesses. That way, if the cap goes off while crimping, you just get a lumpy behind for the rest of your life, instead of losing eyes, lips or teeth.
I always use a single stage to decap live primers, my current method is to place a shop rag around the bottom of the ram, don a work glove and then to turn the least attractive portion of my anatomy in the direction of the press. I then sort of bow away from the press while I slowly pull the handle down. It takes a lot more time to describe than it does to perform and I can probably do eight to ten cases a minute, although I've never actually timed the process.
As I said, I've never had one go off, including a bunch of WWII era '06 with crimped primers that I've decapped over the years, so I may be over-cautious. I will say that I think the operation should be well separated from the actual loading process, particularly if, as in Uncle Richards case, you've got a hopper full of powder right next to the decapping die. I doubt you'd ever have a problem, but if you did, and it was filmed, I bet you'd have a couple million hits on YouTube within a week. Decorum prohibits me from even speculating on what the videos title might be...
Swampman
It just occurred to me that I didn't mention wearing eye protection during my process, not because I don't, but because I've just gotten into the habit of wearing them pretty much all the time when I'm loading.