Affairs are commonplace. Most likely the internal findings from the investigation point to something more troubling/illegal
I'd go as far as to say the second leak helps him a bit, by reframing this as a cheating scandal rather than it being more about him knowingly evading an embargo.
A CEO admitting to an affair with a customer after previously denying it, seems like a sufficient reason for removal, even before you add the geopolitical intrigue.
Like selling hardware to potential competitors of US AI inference services? The extent of the compute laundering has been pretty well covered.
I have a feeling we'll know the reasons for certain when Nvidia's stance on open models and local AI does an about-face.
Could be that breaking embargo and sleeping with spies had something to do with it. Wild guess, I know.
I suspect that there gotta be something else going on with that as well. Maybe someone in the company wanna take his position or something.