Torture claimant dependant to a Hong Kong resident spouse

My cousin married a torture claimant guy. They are now almost 3 yrs married but still waiting for the visa approval of her husband. My cousin is currently a manager of a restaurant amd earning 20k if Im not mistaken. All documents asked by the Immig. were given and almost the same documents were asked over and over again. They have decided that husband withdraw his torture claim and now back at his country of origin, and wait for his visa there.
THE QUESTION ARE, why the visa is taking this long, and how much longer should they wait again? Can her husband get back to hong kong again as a tourist or is he ban for sometime since he overstayed a month or so before he was a torture claimant? I hope you could help my cousin as I have no idea at all. Thank you in advance.