The guy who has trained himself to cock the hammer on his CZ will likely, in a very intense stressful real-life confrontation, or in one of the gun games (IDPA or USPSA when "match jitters" might hit him, put one in his leg, or in the ground. It's one thing to be proficient at the range, and quite another to stay that way when there's more at stake -- like your ranking in a match or your LIFE. Stress is a great stimulant but also a great disrupter.
I respect this view. However, I have watched a video of a veteran competition shooter decock a Shadow he was reviewing that was set up with a manual safety. So... I assume that this kind of gun is used in competition as DA/SA and it is done so by more than a few people, and is 'legal' for competition. I think if this was proven as unsafe, it would be disallowed in competition circuits.
I wasn't addressing the dangers of
decocking in the example you responded to, but to the dangers possible when someone
COCKS the weapon
during the draw.
As for decocking (implicitly) with one hand: if we modify your statement above to address decocking, the important part of your statement was that
if had been PROVEN UNSAFE it would have been disallowed. In that case, I think you're right -- it hasn't been proven UNSAFE.
I've seen it done many times in competition and also at the range, and I typically decock using the off hand to steady the gun and my strong hand to manage the trigger and hammer. But I can easily do it using ONLY the strong hand if necessary.
In a match decocking with one hand isn't disallowed. But, if there is an accidental discharge the shooter will generally be immediately disqualified. Most shooters in a match will be extra careful in such a situation, as they don't want to be disqualified.
More importantly, in a match bystanders are NOT standing nearby, a Safety Officer is present, and the gun is always pointed downrange (generally at an angle so that a round would hit the ground.) There's really no reason to deal with the cause of the problem (inept decocking) as the result is what's dealt with -- by ending the competitor's activities for the day.
Concern about decocking is much overblown! Not that many guns really require decocking. With MOST GUNS, you can use a safety if you want to holster the weapon -- or use a decocker. With most striker-fired guns, you just holster the weapon with your finger far away from the trigger. If you're leaving the range or a match, you just unload and clear the weapon. As much as people worry about decocking accidents, I don't think I've ever seen it happen or heard of it happening, either at a range, at home, or during a match.
It's almost like an urban myth. That said, I've seen all sorts of issues when people draw (present) from the holster -- along with other things that scare the crap out of me... (Ever pay much attention to the ceiling at an indoor range? Or the walls?)