Joyrider,
If it was April 1st I would have assumed this was an April fool.
I think he has been feeding you something still steaming. If he's truely are a PPL(H) holder then he'll know his way around the FAR/AIM and will probably have a copy. Have him find and read out to you the requirements for a PPL(H) especially the section detailing and defining the solo flights and have him explain why he hasn't done any?
In the meantime you may wish to advance read - ss 61.109 (c) and ss 61.87a
Then maybe you'll visit the FAA website and confirm with some basic details whether the fellow in front of you legitimately holds the licence or has "borrowed" it.
From my recollection a "supervised solo" usually meant your instructor was present at the airfield whilst you did a few circuits as opposed to being off on a cross country where he had little ability to watch your actions.
IMHO the flying skill requirements to obtain an FAA PPL(H) are a tad more challenging than the JAA requirements given the solo cross country elements.