In explaining the lack of a body, the doctor explains to Denise and Alan that Daniel Post donated his remains to "medical research or transplant sites." As a patient who died of cancer, none of Post's body parts would be suitable for use in transplants.
The procedure in the trial made his remarks then the defense and that was it.In a real trial the Prosecutor makes closing arguments, then the defense, then the Prosecutor makes rebuttal arguments.The reason the Prosecutor makes rebuttal remarks is because it is the responsibility of the prosecution to prove guilt.