Pilot is only required to file a report to the NTSB w/ in 10 days of an accident barring some requirements for immediate reporting which on the surface of the story doesn’t appear to have met said requirements.
In the news story it said the pilot did notify the NTSB. Having said that the pilot could have been more pro active and notified the local FAA (FSDO), as well as local law enforcement so as not to have wasted resource and time Looking for em in the water, and whatever other time and manpower was wasted in finding the person. Of course with a nose over like that - there is a good possibility they took a good knock to to the melon, and could have not been in a right state of mind…..