A few points to note
1. Why during the time when Su was arrested, ncm, oyk and the rest did not declared they had met Su and had dinner with him? The number of headcount present in the dinner was not like a few hundreds, just about 10 pax, so to claim that they doesn't know him does not make much sense.
2. When ncm tried to leebute during his course of work, he will bound to meet people and businessman from the pte sector, He surely cannot apply this statement to this dinner and photo, as Su apparently wasn't any employee or stakeholder of any pte company.
3. Why now Sam boi has not been questioned about details and agenda of the dinner, since he was the host.
Sam boi is the key person to provide information.