When discussing the military 1911 incidents...
Keep in mind the sheer numbers of people, length of training and previous handgun experience of the users. During WWII, tens of thousands of young men were plucked from their daily lives, taught some very basic skills and sent into theatre to fight the enemy. Many of them had little or no firearm experience and add the additional stress of combat, it isn't hard to imagine some accidents occurring with the weapon.
Are DA/SA or DAO semiauto triggers safer? Probably.
However, SA revolvers are safer than any of them. (The trade-off is not worth it though.) Equally, it's easier to teach a person to be a better shot with a 1911 than a M-9 because of the better trigger. Which is one of the reason the military stuck with the 1911 for so long even when newer and "better" designs came along in later years.
Sic Semper Tyrannis