There are inconsistencies as to how many children Hooker has. In the pilot episode "The Protectors", Hooker is seen only with a young daughter and son. In the first season episode "God Bless The Child", he also has a second daughter who is a teenager. But then throughout the second season, only Hooker's two young children are mentioned. But then from Season Three forward, Hooker only mentions his small daughter.
The exterior shots of Hooker and Romano's patrol car almost never match the background processing plates used for the shots of the car interior. For instance, if the exterior shots show them driving through a business district, the interior shots will show them driving through a residential area and vice versa.