In the months before the February hearing, Heilberg and the prosecutor worked to hammer out a plea deal. Since Heilberg is an experienced defense attorney who has likely represented slow-in-the-minds before, he takes pains to ensure Chris understands the situation and fully agrees to the deal. Chris could have been honest and told Heilberg that permanent separation from 14BC and Barb were red lines for him, but he lies and says he agrees to the deal instead.
On the day of the hearing, Heilberg and the prosecutor enter the court confident that Chris will accept the deal and that they just need to make it official in front of the judge. During the hearing, Chris states that he didn't fully agree to the deal and possibly attempts to negotiate in a fashion similar to what is
documented in the CWCki. Ultimately, it's the reveal of Chris's lies to his defense attorney that gets him sent off for a competency evaluation, not rejecting the deal or outbursts. The court then ends the hearing with a continuance.
The act of lying to one's own attorney is a blend of retarded, deceptive, and counterproductive that is typical of Chris. Getting sent off to a mental hospital because of a giant tard tantrum just feels too bland in comparison.