In Melbourne and Adelaide, this episode aired in the week following the final episode of Hunter (1967), which also starred Gerard Kennedy.
Frank Banner had the same crew-cut hairstyle that had characterised Kragg, Gerard Kennedy's character in Hunter (1967). This is due to the immediate turnaround between the two series - the interior scenes for the final episode of Hunter were being taped around the same time that the exterior scenes for the first episode of Division 4 were being filmed.