How did he manage to leave with A levels at age 16? That's GCSE year and A levels would take an extra 2 years past that. So either he's an extremely capable lad (99% average implies that) or he left at 18 like everyone else.
We've had a thread about someone who flew 737s aged 19 before, though his Dad was the chief pilot, so it got a mixed reception on here.
I would have thought Oxford passes out many 19 year olds to be honest?
He does sound very talented though with that average and if he took GCSEs and A levels early. Certainly not your average intellect.