Dragonair also had fun with this...
Believe Dragon also had fun with this issue afew years back when a 60yr old Captain was offered a 2 yr extension in the RHS in same aircraft/same company, only to find once he had commenced extensions that he was limited to shuttles between HKG & Taiwan with the odd flight elsewhere - I think he couldn't fly in to China if my memory serves....similar reasons to above...
I think he's now fully retired...
Not sure what HKCAD's view was of the the rules etc as I cannot recall accurately but I'm sure that one of the HK bods will do so...
Z.