First appearance by Patrick Stuart as Dr Zee, replacing Robbie Rist in the part.
Colonel Boomer is seen wearing a pendant on his uniform that was previously only worn by Commander Cain in The Living Legend (1978). Despite being a bridge officer now, Boomer also personally leads a Viper Attack Wing wearing his old pilot's uniform.
Dr. Zee mentions that the Cylons have evolved and developed new technology. In the original script, two new human looking Cylons were to be introduced during the attack on the Delphi, named Andromus and Andromicus. This explains the brief appearance of a new model of Cylon Raider during this scene. While the characters were eventually dropped, they were combined into Andromidus in The Night the Cylons Landed (1980), which re-uses the scene of Zee and Adama that was first seen here.
In the script, the Stanford Chemical Plant was originally called the Paradise Chemical Plant. This name was changed to when it was decided to use stock footage from Short Fuse (1972) for various shots of the chemical plant.
During the filming of the fire sequence, a large beam was supposed to fall from the top on a cue from director Vince Edwards, but didn't. After yelling cut, Edwards walked onto the set and inquired what happened to the beam. At that moment, a prop man, assumed he just received his cue and finally dropped it, nearly hitting the director.