Megan,
"The second SCT controller said that, when he received his first radio communication from the accident pilot (when the pilot advised that he was starting a climb to go above the layers), the pilot spoke as if the flight were receiving ATC radar advisory services (which it was not). "
The first Controller denied the pilot's request for Radar Flight following telling the Pilot the reason was that he would be losing Radar and Comms with him due to his low height above ground and directed the Pilot to Squawk VFR (1200) on his Transponder.
That Controller told the Pilot to contact ATC when he was closer to Camarillo Airport....but did not specify which ATC Unit to contact.
The Pilot appears to have continued to monitor SCT ATC and upon entering IIMC and electing to climb to VMC conditions.....the Pilot informed SCT of that.
The second Controller having no information about the Aircraft....initiated the standard identification process.....seconds later it was all over with no response from the Pilot or the Transponder.
The bold text in the quote is pure supposition by whoever is being quoted and is not borne out by any information, data transfer, or recorded communication that would indicate that being a fact.
I see the listing of Spatial Disorientation as being the Primary Probable Cause also to be speculation not borne out by any direct confirmation.
It is probably the final cause but it was not proven to be "the" probable cause.
Did the NTSB actually rule out all other possibilities as the cause of this crash?