1. There was absolutely no reason for him to testify, so it’s not a surprise that he didn’t
2. The prosecution / Patrick Fitzgerald produced incredibly weak case, relative to what they could do. They limited almost everything to IRS case.
Blago can skate or receive a very lite sentence in what could have been a blockbuster case by Fitzgerald, but this was not a Liddy / Rove / Bush case, so he went with the minimum effort, just to get a “win” on the resume.
Seem to remember when Obama recently went to Chicago one of his first acts was meeting with Fitzgerald . . ..