Apparently Lasik and PRK-treated eyes can be picked out easily using corneal topography. This is used by the US military for screening.
Your friend, having lied to the CAA and his employer, will have to perpetuate the lie at every medical in the future. If he does get caught out, and he may well do, he will not only be out of a job, but also probably prosecuted.
I underwent lasik myself and aim to fly commercially at some point. Despite the success of my treatment, I would not consider lying about it. If I and people like your friend believe our eyesight is good enough, we should fight our case. The cockpit of an aircraft is a busy enough place without the sort of extra baggage your friend has brought into it.