I realise the aircraft appears to have been re-registered in August 2011. Even with the records one year out of date ?? then the period 2008 to 2011 is still showing as not registered.
I see several things;
The record keeping not terribly accurate, or at least the website side of it.
The three years unregistered. Maybe it was just parked up.
The neighbour reporting that the pilot flew regularly. Maybe he had access to another aircraft there.
The chap doing the inspection would have a fair idea of the history of the machine. What is the expectation of him if he believes the aircraft has flown whilst unregistered ?
The machine being registered now makes it an RAAus matter I believe. They will know if he was current etc.
I don't have a problem with two-seaters carrying 3 souls-on-board. I don't think the emergency exit CAO makes it anymore legal as such but it comes down to safety, as in the seating, restraints and controllability. Both flight controls and weight and balance. I accept aircraft like the C150 can be modified with a child seat.
I recall talking to the CAA about a helicopter that had only logged 6 hours in the previous year. After the subsequent crash the son was on TV saying what a saint his father was and how he was teaching him how to fly it. The son must have been a bloody quick learner, especially since his father had never been an instructor. Although the conversation never featured in any findings I am betting the staffer is still wondering what if..
You can rest assured that the investigators will be feeding from all the above.
This is where the engineers get unwillingly dragged into someone else's problem. Now the spotlight is on him also and he probably did the job for a pittance anyway.
I feel for the pilot and his family, they appear to be pretty beaten up. I can only imagine the circumstances of the flight... I am sure it seemed like a perfectly good idea at the time. This is probably more of a case of real bad luck than any form of negligence or stupidity.
Then again the outcome could have been a whole lot worse.