It sounds like there wasn't even twenty minutes worth of fuel left if ATC's suggestion of Barton was declined, it's only about 5 minutes further on. Good decision in the event though, as it would also have required an overflight of central Manchester.
Press-on-itis and got out of his depth?
p.s. Unfortunately Offshoreigor has it about correct re. the attitude of the CAA, they will go for a soft target if possible.