Indicating that script revisions occurred during filming, Barnaby comments to one witness that "a boy was found murdered in the woods yesterday", when in the final version the victim is not found in the woods, but staggers back to Devington school and expires in the quadrangle.
In the scene where Marcus Heywood enters the kitchen, lights a cigarette and slowly walks through the kitchen before stubbing the cigarette out in a pudding, the cigarette keeps switching between his right hand fingers and his left.
When Troy and Barnaby interview Dennis Carter in his cottage, Mr. Carter gets up from the table and stands in front of an outside door. On the bottom of the door is a handwritten sign that reads "THIS IS A DRESSED SET. KEEP OUT."