In the side shot of the witnesses on the stand, you can clearly see caster wheels on the legs of both the Defence and Prosecutor's tables. Presumably, this is for easy movement when setting up shots, but would be highly impractical in a real courtroom.
In the sanity hearing, the judge seemed surprised to see Perry when he came forward to ask questions of August Dalgran. But the judge should have seen Perry before then, given that the room was very small and that Perry was seated across from the judge and apart from the others who were there.