Update!
So. I tried to get a colleague to go around and view the flat. First attempt failed - after arranging the viewing time, the following day the agent cancelled it and said the flat had been sold. (It hadn't).
I tried another listing.
This second attempt... got cancelled three times by the landlord who eventually told the agent that no one in his entire family was free to pass the key to the agent until at least June (this was a week ago). It seems likely he is [rightly] scared of viewers being me coming to get evidence from the flat to show he has stolen my money)
But the second listing had better photos in it than the first, and I could see that the walls of the flat had not been repainted, nor had the scratched floor tile been replaced. Essentially, no repairs had been done at all, over 5 weeks after I had moved out.
I decided to get some extra evidence and I got the management office of the apartment to verify whether any contractors had visited the apartment at all in the period since I had moved out. They confirmed that no contractors had been there at all.
So! The original quote I got was likely not obtained from someone who had been in the apartment... and it seems extremely unlikely any repairs have been done at all.
On Monday I filed my case at the Small Claims Tribunal. (By the way, if anyone is reading this thread in the future, it is incredibly easy to do this. You fill out two forms, and there is a template you can copy for the deposit claim form. It takes about 10 minutes and you pay just $80 HKD. You don't even need an appointment).
The question I was going to ask is: is it worth going to the police? I have reasonably good evidence the landlord has taken $34,000 from me on false pretences. He made up a quote, has refused to confirm he has even done any repairs (I messaged to ask) but previously claimed in Whatsapp messages he did do repairs at the start of May.
It sounds to me like fraud. Yes, the Small Claims Court will give me my deposit back, or nearly all of it presumably, but this looks to me more like criminal behaviour.
What do people think?