The thing about that video, why didn't they support the wires? The other thing is I cannot believe is that they didn't use 1 metal box in the whole job...
I have, twice. Both times we used plastic bushings in the studs and supported the NM with Colorado Jim's.
I guess I am surprised that the guy died from 110volts. I get zapped all the time with 110V but I guess it takes a bad heart or something. It doesn't sound like he was connected through the load.
I was hit real hard once by 120. Flood light on a fascia board had 1/2" EMT, old stuff, no ground. I grabbed the EMT and my bare leg (yep - had on shorts) was on the metal Parapet wall. I could not let go, I had to throw myself off, and landed on my back on the flat roof. I would say that it was worse experience than when I touched 277 while changing a ballast.