That's just crazy.
I think maybe instead of shutting off the engine, he may have dumped the collective, letting the helicopter free fall. The Sikorsky S-76B I believe it was, has turbine engines, and you don't just shut those off and restart them. That's dangerous as there are a lot of things that can go wrong on a restart, and helicopters don't glide real well with no engine. You can still auto-rotate, and land, if you're in level terrain and good weather conditions.
After reading an article just now, it sounds like the pilot got vertigo, which is very easy to do in weather. It's worse in helicopters because they are inherently unstable. That's why IFR helos have auto pilot.
"Bryant's helicopter left Santa Ana in Orange County, south of Los Angeles, shortly after 9 a.m. and circled for a time just east of Interstate 5, near Glendale. Air traffic controllers noted poor visibility around Burbank, just to the north, and Van Nuys, to the northwest.
After holding up the helicopter for other aircraft, they cleared the Sikorsky S-76 to proceed north along Interstate 5 through Burbank before turning west to follow U.S Route 101, the Ventura Highway.
Shortly after 9:40 a.m., the helicopter turned again, toward the southeast, and climbed to more than 2000 feet. It then descended and crashed into the hillside at about 1400 feet, according to data from Flightradar24.
When it struck the ground, the helicopter was flying at about 160 knots (184 mph) and descending at a rate of more than 4000 feet per minute, the data showed."
https://www.adn.com/nation-world/2020/0 ... -choppers/
4000 feet per minute descent is extreme! That's a helicopter that is out of control.