Reloading is as "Safe" as the 'person' doing the Reloading; nothing more and nothing less. If the person doesn't do the work properly some very "<span class="ev_code_RED">Bad Things</span>" like this can happen.

I looked as closely as I could at the primers that were present and the one on the Right appears to have been properly seated and the others don't appear to be "flattened or cratered" which can be signs of over pressure. But, that beings said; I'm guessing that this was the "ONLY" double charge in the cylinder at the time of the shooting. If the one "unfired" cartridge had also been "Double Charged" then - I believe - it would have created another Ka-Boom and more of the cylinder and likely more of the gun would also be gone.

I've 'looked into' a number of "destructive" firearms accidents since my first one in late '69 and this one has all the "signs" of being a Double Charge of Powder. Operator Error.