(1.) Government imposes stamp duty on non-PR property transactions.
(2.) Property developers allow some time to pass and then ...
(3.) Sell off individual hotel rooms as "investments". The "investors" can live in their hotel rooms but would have to pay rent to the mgmt company who will then pass it back to the occupant, who happens to be the owner/landlord.
The hotel in question is in Kwai Chung and, in the clips of video from the news broadcast, looked suspiciously like a regular old faux-luxury housing estate. Reporters found two proud new owners of hotel suites to interview: a Mainlander (who proudly admitted that it would be for his daughter to live in while studying in HK) and a Hong Konger. I'd imagine finding the Hong Konger must've taken some time.
Only in Hong Kong.