another theory

So Mr. Luk is 'assisting' the ICAC with their investigations on events 'before' he became a director of wah nam. I'll throw another theory on the pile. WR, Cusack and the other 2 who suddenly resigned at the same time are all involved in some kind of corruption and Mr Luk is providing the evidence. They all leave the company prior to the investigation going public to save face. Otherwise the company would have to report they are involved. Fits in with Mr luks stance that he does not intend to step down.