When going to visit Volkoff in prison, the voice on the intercom says: "9205, you have a visitor." But his jumpsuit says prisoner number: 121196 throughout the entire episode.
During the game of chess, after Alexei Volkoff blocks the check by his bishop, the computer's bishop captures the knight. However, during the capturing, Volkoff's bishop that originally blocks the bishop is shown to be back at the original square. When Volkoff delivers the checkmate, the bishop is back to the square it is supposed to be.
Volkoff says the killing agent for the Norseman weapon is thorium and that it is very rare. Actually, thorium is as common as lead, far more common than arsenic or tin and less toxic than arsenic.