Over water IMC descent to find VMC conditions.....now who flying offshore has never done that?
Granted it is safer with Radar installed and working....perhaps even having an installed and functioning Auto Pilot.
Doing a descent hoping to find VMC over uneven terrain...no thanks.
We will. not know if that descent was by intent or was the result of a loss of control by the pilot.
As he called SCT to report climbing.....and the very short time between that transmission and loss of Radar Contact would suggest a rather abrupt change in plans if it was intentional.