Inventions - S3-E22
Other mistake: After Johnny and Roy are seen carrying the semi-conscious worker during the chemical leak, Captain Stanley tells Mike to get the life gun, and tells Chet to secure a lifeline, then before he mentions getting the guys from the catwalk via the lifeline, we hear Captain Stanley tell the Battalion Chief (into his handie-talkie), "Battalion 14, Engine 41," even though he's Engine 51, not 41. Additionally, when Cap tells Chet about the lifeline, two firemen behind Chet are wearing helmets with no company numbers on them.