That was a trivial thing in comparison to this, and no man should have to testify about himself in a trial against him. That is a great princible of Freedom. Why say nay to it, which you do in practical effect? If one hews to the another great princible -- that of presumption of innocence -- why then what a man doesn't say sshould be held to speak for him. Your stance is affine to presumption of guilt, which is a stance poison to Liberty.
I didn't say he had to. I just said he should if he really wants people (like the jury) to believe he is innocent. It's simple logic. If you are innocent and your life is on the line, say you are innocent.