While Mrs Barford threatens Father Brown with a log fork from the fireplace, she holds it horizontally when the camera is from her viewpoint, and vertically when from Father Brown's.
Father Brown tells Blind 'arry that he will be gaoled if he is found to have committed perjury. Perjury is wilfully telling an untruth or making a misrepresentation under oath. Giving a false statement to police does not constitute perjury as it does not involve swearing an oath. He could, however, be charged with giving a false statement. However, while talking to Mr Laughlin in gaol, he says "if 'arry has lied under oath." This implies that the statement made WAS under oath, which IS perjury.