Originally Posted by
runway30
...can I suggest the colour blindness is a red(?) herring?
I wouldn't say so because if his alleged colour vision deficiency is a fact, then it would have prevented him from holding both the night and instrument ratings. Anywhere, UK, EASA and FAA. Unless he got an excemption of some kind (I once had a student who fought battles with the authorities for five years before he eventually got his night rating because of colour vision issues).