Senator Elizabeth Warren (D) has called for an investigation into Elon Musk and his company, SpaceX, Bloomberg reported on Sept. 12. The U.S. Congress should investigate "whether we have adequate tools to make sure foreign policy is conducted by the government and not by one billionaire," Warren said on Sept. 11 in Washington, D.C.
While that’s complete bullshit and absolutely an abuse of the system as it’s intended to function, it’s also technically legal, because the person occupying the office of the president at the time (and I know exactly to whom you’re referring) was a duly elected officer of the government - not to mention, the head of state.
The difference here is that Elon was never elected or appointed to any role in the US government, and thus cannot serve as an official representative of the US in any capacity. The law is quite clear and unambiguous on that point.