i did read about it with LOTO prodcure but some disconnetion switch can actally go bad and my simple rule is after lock out and tag out i use the voltage tester and i mean i use two diffrent type of voltage tester to make sure it is 100% dead voltage in the area where i will be doing work.
most important part is use common sense regarding what voltage the system is running low, med , high voltage catory area so as i stress it again run the tester twice to make sure it is dead.
but some case i know some peoples they are in the hurry or careless or not thinking for some reason it can be very dangerous with it like dont have time to verify the voltage is dead etc and on med and high voltage stuff the other issuse is proper grounding it [ i will leave that subject somewhere else. i will keep in the point here]
and some company don't have any safety traning program and i wonder why some company want to cut corner to keep the cost down without taking someone life there.
myself i do belive in safety training it do pay off to keep aware with sisuation around you.
Pas de problme,il marche n'est-ce pas?"(No problem, it works doesn't it?)