Michael's appearance before the Senate committee was his first, it was documented, and it was public. He was inexperienced in such proceedings. In a criminal proceeding, even an honest mistake one makes when testifying can subject one to a perjury charge.

Why he testified at all or didn't invoke the 5th amendment is beyond me. Whatever information he provided to the committee would either be true or a lie, or would either be new information or would confirm what the Committee already knew or suspected. As is true of Mafiosi generally, government cannot confirm their ownership of anything since Mafiosi are not inclined to document such ownership unless it is legal ownership. There was nothing for Michael to gain by admitting his controlling interest in the hotels (Of course, he could have avoided answering any questions by invoking the 5th Amendment).

One thing I teach my classes is that whether you are simply a witness or a person of interest in a legal proceeding, you cannot be sure of law enforcement's strategy or your potential culpability.

Although he was living high on the hog, I give Michael credit for having the necessary and legal financial resources to sustain such a lifestyle just as Vito must have done.