Producer J. Michael Straczynski met Everett McGill at a restaurant, and later decided to use him in the episode "Severed Dreams", but couldn't remember his first name. He told the casting director to get "that McGill guy". On the day of shooting, Straczynski found Bruce McGill waiting on the set. There was no time to correct the mistake, so Bruce McGill was used.
The character of Major Ryan was an addition to the script when it was discovered that 'Robert Foxworth' could not return as General Hague. This resulted in an outtake in which Bruce McGill, upon his character boarding Babylon 5 and being asked where General Hague was, replied "General Hague is doing Deep Space Nine. He was double-booked by his agent, there was nothing to be done. So you'll have to do with me sir."
Jerry Doyle broke his arm for real during the filming of one of the battle scenes. Unfortunately the scene showing him with a broken ankle was filmed before the accident and later episodes ignored the broken ankle and show Jerry with an arm cast, explaining that this was the injury sustained in the fight.
The scene where Delenn (Mira Furlan) snaps the Grey Council staff in two had to be shot several times because, try as she might, Mira couldn't break it. The staff finally had to be sawed partially in half by a stage hand.
This episode was purposefully scheduled at the midpoint of the series' intended five year run as a payoff for the preceding story action in which the station command's period of growing suspicion and then covert action against the villains of the series has ended and now they have to fight out in the open at last.