Indeed - I can quote a counter example of a (white British) woman here with her bf who left HK for the first time after about 4 months for a weekend in Macau, and was taken aside by Immigration when she reentered and given the "small room interrogation" as they went through her wallet looking for evidence (such as local bank cards) that she was indeed living here. Not finding any they made it very clear that they suspected she was and that she was being "watched".
Some people get away with living here as illegal immigrants for years, and some get caught within a few months. Being an illegal immigrant is a risk anywhere - up to you whetehr you wish to take that risk, but it would be wise to have a Plan B to cover either being refused re-entry or being told "you have a 14 day visa to sort out your affairs, after that don't come back for at least 6 months" (I know at least one (white, British) person that has happened to).