When Ashe, Sgt James, and the police sergeant arrive at the bomb's location the policeman is no longer wearing his medal ribbons.
Brian Ashe is shown wearing his Sam Browne belt with the strap over his left shoulder. In fact the strap should be over his right shoulder.
Ashe is met at his first bomb site by a police sergeant wearing the ribbon of the Police Exemplary Service Medal. This was not instituted until 1951.
On Ash arriving at his first bomb site, one of his men kicks a cabbage which easily flips over. The field is obviously just cabbages laid on the ground, not an actual growing cabbage field.