Dwarfs and diving

I am currently working as a Divemaster and have a friend here on holiday who has expressed an interest in diving. My friend is a dwarf. I introduced my friend to one of the instructors here who after establishing that he is medically normal and fit to dive agreed to enrol him on a Discover Scuba Diving course. However the manager of the shop has express concerns about allowing him to dive explaining that he has the physiology of a six year old and the rates that he absorbs and releases nitrogen would be very different to that of a normal sized man of the same age thus making any dive tables or computers unreliable in calculating nitrogen levels in his body. This he says could greatly increase the risk of DCS.
I would be grateful for any advice you could offer on this subject.

Acondroplasic dwarfs have the physiology of their age. Hormonal (Hypophysis) dwarfs may have had other reasons than the altered bone growth for their small size. However both have a stable situation when grown to maturity.
The assumptions regarding altered inert gas uptake and release are unsubstantiated.
In the absence of any medically significant contraindication to diving and provided that an appropriate size can be found for the diving equipment to be used, there would appear to be no reason why your friend should not dive.