Another case where the right of the accused triumph over justice for the victim. I see the bloody hand of the ACLU in this.
Does the name JoJo Giorgiani ring a bell? My memory's a little hazy at this point, but back in the early '80s a 300+ pound rapist was spared jail time because the prison conditions would have been bad for the poor baby's health. I don't know what ultimately became of him; hopefully he got crushed under the weight of his own fat.
Let's assume that he really cannot communicate facts or ideas to another person and that he's not playacting. And suppose further, he has a perfect alibi but cannot tell his lawyer about it. That's an example of the reason for the rule that you have to be able to participate in your own defense. It's really not such a bad rule.