The DOJ investigation puts Burr in a tough spot. If he testifies before the SEC, his testimony can be used against him in a criminal case by DOJ. But if he takes the Fifth, that can be used against him if the SEC brings a case against him.
Check out my discussion of this case with Michael Schachter, who prosecuted Martha Stewart when he was a federal prosecutor, on my #OnTopic podcast: https://t.co/2JPFwSqnkd