That would be correct. Once his plea bargain deal fell through, he was left with no option but to plead guilty or not guilty. I looked at that a couple of times myself, but forced was the correct word to use.
He was forced to plead. No one forced him to plead one way or the other. Maybe I read too much into the wording, but it seemed to me that the intent of the wording was to imply he is not guilty and forced to say that. He could have just plead guilty as he was going to in the previous plea deal.