A couple of thoughts:-
- From the statement about fuel, this chap believed that he was arriving with at-most 6 gallons of fuel at Shoreham. Is that enough for a go-around, diversion to Goodwood, and a brief hold in a Seneca. Sounds very tight to me.
- Fuel gauges are not required by law to be accurate except in one case - they must accurately read empty when the tank is, well, empty (as N14HK says). So the chap should have arrived knowing that his tanks were empty. In those circumstance why was he flying a powered approach (by definition, he wouldn't have hit the house otherwise) instead of a high glide approach where an engine stoppage should end on the runway.
- So far as I know he didn't declare a fuel emergency, which would have been an obvious course of action.
I don't like CAA prosecuting people in most cases, it rarely helps anybody - but in this case I think that they have a better case than usual, albeit that I don't think that the fuel-calc is the main offence.
G