Near the end where Karl Drake (Duncan Preston) attacks George Cowley (Gordon Jackson) from behind, we see Cowley spray Drake with white foam from a fire extinguisher cylinder. The front and back of Drake's jacket are well covered in thick streaks of the white foam as he runs away from Cowley towards a short tunnel. When we see Drake reappear in the next shot exiting the tunnel and he is confronted by Bodie and Doyle, Drake has a few small splashes of foam on his front and hair and none whatsoever on his back.
During the fight scene in the pub, Bodie is initially not wearing a vest under his shirt - his bare back can be seen. Later on he is wearing a vest tucked into his trousers.
Around 00:18:59 Halloran while talking to Bodie and Doyle says "They went for Gillam, Temple-View Chief Accountant." The company's name is 'Temple-Blake'.
Nearer the beginning, Sam Burton calls out to his wife Jenny (as she is credited) to tell her of his being called up for jury duty, but calls her Linda, which is the real first name of the actress Linda Goddard, who played Jenny Burton. This may have been an error on the part of the late Brian Hall, who played Sam Burton, just as there was a young lady in a movie with Tom Cruise, who calls him Tom, even though that was not his character's name.
The newly-built house appears to be a much older dwelling from an earlier period than the late 1970s.