How things have changed!! lol!! During my time in the industrial sector, working live was part and parcel of being an electrician. By the sound of it, most of you would cringe at the things we were expected to do, to keep the lines/plants running. We were actually taught how to work live during the latter part of our apprenticeships, complete with fully insulated tool kits...
No it wasn't just a case of jumping into things willy nilly, ...any and all precautions were taken that could be taken, and you never worked live alone, but work live we did and on a pretty regular basis as well...