Aren’t helicopter pilots required to fly “under the hood” like conventional pilots?
"Conventional pilots", i.e. Fixed Wing (airplane) pilots are not required to fly under the hood, unless they are training to obtain an Instrument-Airplane rating. Then they undergo extensive Simulated Instrument Conditions (under the hood) training and Actual Instrument flights (in the clouds). "Fog" is clouds on the ground. Not the best place to be flying IFR (Instrument Flight Rules).
Helicopter pilots can slso obtain an Instrument-Helicopter rating by undergoing the Instrument Training in a helicopter. Kobe Bryant's pilot was Instrument Rated. However, he was not "Current", that is, he had not flown under actual or simulated Instrument conditions recently. The helo he was flying was capable of being certified for Instrument flight, bit IIRC, was neither equipped nor certified.
I have both an FAA Instrument-Airplane and a US Nsvy/USMC Standard Instrument Rating-Fixed Wing & Helicopter. During my initial Instrument training, my Instructor intentionally put me in a vertigo inducing situation. When told him I was experiencing vertigo and passed control of the aircraft to him, he waited a few seconds before announcing that HE had vertigo and I had to assume control. He wanted to see if I could fight through my vertigo and still fly.
That was one of the most difficult things I have ever done. After a lifetime of trusting your "seat of the pants" and inner ear balance to suddenly, forceably IGNORE them both and TRUST your flight instruments was almost agony. That is why actual instrument flight requires Training, recent practice and discipline.
I have hundreds of hours of Actual & Simulated Instrument flight in both Fixed-Wing and Helicopters, nearly all in multi-pilot aircraft. I've only once flown into "inadvertent IFR" in a helo, single pilot. Bad decision making on my part, getting into that situation. However, I was able to transition from visual references to watching my instruments, set a strong positive climb rate and pop out on top of the low cloud layer. i learned from that.
"There are Old Pilots and there are Bold Pilots. There are no Old, Bold Pilots"