Obviously he must be punished, at least for having an affair with a subordinate, which until now is the only thing that is certainly wrong, from the PoV of the company.

However, if he is fired, that is more a punishment for the company than for him, because he is extremely rich and at the age of retirement, so he does not work because he needs to, but just because he enjoys it.

A real punishment for him would be to lose without compensation a part of his NVIDIA shares.

If it is ever proven that he broke any export control law, then a punishment for that is a decision for the judicial system.