Problem hasn't returned. It persisted for a full day and a half. All I did was remove both solenoids and electrically cycle them with a 12 vdc source. I didn't clean them, they looked pristine. I then removed the cam position sensor, wiped it off and tested it electrically. It worked as it should, cycling between 5v and 0v when triggered by a piece of metal. Following this, I started the car and it's working ever since. I'm concerned I have a problem that can return at any time. The solenoid and sensors are extremely easy to change. I have a spare sensor in the boot and a set of electrical leads to cycle the solenoid if need be.
Funny thing. This all started when I was starting the car. I got the bright idea to teach my window regulators immediately after starting the car. All of a sudden the engine started to miss and then shake violently and finally stall.