This Dec 18 Hawaii incident sounds eerily similar to the crashes in 2018/19 that grounded the 737 Max. The planes take off normally but then are thrown into a steep dive. This time it was a Boeing 777, and the pilots managed (barely) to avoid hitting the ground.
And still another incident (Jan 10) with a Boeing 787 leaving Qatar, with another steep descent following takeoff (link below). As with the Hawaii incident in Dec, they managed to recover at an altitude of 800 ft -
1. Nothing about the incident was heard until now (two months later). 2. That the pilots didn't report the incident or return to base after a loss of control incident. 3. That the aircraft manufacturer apparently wasn't apprised of the incident.
I say "apparently" because IF Boeing was aware of the incident? They would have announced an investigation into the circumstances of the flight. And it would've been ballyhooed incessantly in the news.
This fact that the flight crew was remanded by the airline into "more training" tells me that this was a case of pilot error. My guess is that they had something configured incorrectly or made some sort of error that commanded the aircraft into a dive. They figured it out in time and continued the flight.