Have a friend who is now retired from LE after about 26 yrs. About year 21 or so, as a Lt. in detectives, he had a ND. As a uniformed officer, he had carried a 6" Python, and had extensive experience with them. One day while he was in his office, a younger uniformed officer brought in his Python he was having some trouble with and asked my friend to look at it. My friend watched the uniformed officer open the cylinder, dump the cartridges, and close the cylinder. The officer handed the revolver to my friend, but, my friend neglected to open the cylinder to check. He put the gun up next to his ear, with the long barrel pointing up and backwards behind him. He DA the trigger a couple of times listening to the action and then BOOM. Fortunately, the gun was pointing in as safe a direction as possoble in a city building in a relatively large city. It took out the window in his office, him which was on the 6th floor.
Unfortunately, he lost the eardrum in that ear. The doctor said that it looked as though it had been removed surgically, it was so completely gone. They were able to build a new eardrum, but he still does not have the hearing he used to have.
We have been good friends for over 35 years, and worked with him for about 4 of those years. I know that he knew better, but he admitted that he "saw the officer dump out the shells, and just had a lapse in habit of checking, just didn't think about one of them hanging up in the cylinder." I know that even though he damaged his hearing, and had to take a lot of ribbing from other officers, and crap from superiors, that he is thankful nobody was seriously injured or killed. It was pointed in a safe direction, at least as safe as up in a city can be.
If anybody gets offended about you checking after they have checked, s@#*w them. It's somebody's life at risk!