Well AndyBrown, HK labour law might say so, but no such thing exists in OZ, US, Canada or Europe.
Contracts on bases are enforceable and will be followed.
A few years ago DFO RH, GMA PH and GMA/DFO AT started messing around with contracts on bases, ask them how that went....
So yes, in HK things might go a little bit different in the coming weeks from what most are expecting, however bases won't be messed around with.
That would actually increase overal cost dramatically so there is no way to justify that by senior management.