I don't think a turn causes a logon. This would generate endless logons when airplanes fly holdings or so.
To me a logon would happen after some kind of system restart. As if you boot your windows computer.
I do not see a difference in the sequences at 18:25 and 00:19, that makes it strange when the latter was very firmly associated to a power up.
I would believe that this system behaviour is essential to the investigation and it should be replayed on board a real life flight. My feeling is that there is more involved than just a manual intervention by someone onboard.