Hilico raises a bit of a grey area, concerning the type of licence required for corporate flying. Quite a lot of private pilots fly corporate aircraft without being nicked by the CAA. The argument goes that the flying of that aircraft is incidental to their employment as an accountant (or whatever), and that since they do not get remunerated for the flying, they don't need a professional licence. JAR FCL has changed that a bit, but PPLs still do this sort of flying.
(There are at least a few PPLs who blatantly break the rules but that is another story)
However, regardless of the type of licence held, it is not sensible to "give someone a conversion" and then just let them loose flying typical corporate helicopter flying. A pilot needs more experience than you gain in a PPL(H) course, before being let loose on such operations.