http://www.hongkongairport.com/eng/t...from_hkia.html
http://www.nwstbus.com.hk/routesearc...88&intLangID=1
N11 From Airport (Ground Transportation Centre)
Daily Headway (mins)
00:50, 01:20, 01:50, 02:20, 02:50, 03:20, 03:50, 04:20, 04:50
That's just one of MANY night bus services from the airport to various locations all around HKG.
I assume had it been a city where there is no night public transport, CX might be probably willing for some generosity, but given this is HKG, and you had definitely means of public transportation during the night (a bit less comfortable than taking a cab maybe..) I'd think twice of sending in such request..