or are willfully avoiding the truth. There is NO OTHER reason. The mysterious other reason CANNOT exist.
In truth, he probably DID consult with his lawyer because you can't just whip out the fifth if you feel like clamming up.
There actually has to be a real and tangible concern he may incriminate himself. He likely consulted with his lawyer who instructed him to take the fifth or the lawyer agreed with UC's already existing desire to take the fifth.