Hi guys I'm also going through HKG KTM and have 13hrs Transit and have same question. As i found, if you have through ticket from Cathy pacific to dragon air(remember only dragon air) you do not required visa but if you have another airlnes beside dragon air then you need visa even for half an hour transit.

This is to promote dragon air. Tell your travel agency to give you print out that show we did not required visa.

good luck and see you in Nepal.