Just culture?!
This is gross incompetence bordering on negligence frankly.
1) The camera should arguably not have been on the flightdeck
2) Failure to connect movement of seat with aircraft pitch down
3) Failure to identify movement of sidestick (did the captain even touch it during the event?!)
4) Failure to control speed in the ensuing dive
5) Why did this take so long to come to light - was there an attempt to cover it up?
Thankfully the actions of the copilot (having crawled back into the cockpit via the ceiling) brought some order back into the cockpit.
Several people were badly injured and a fully serviceable fleet grounded with the associated severe knock-on effects thanks to this incident - If I hadn't read it I wouldn't have believed it.