When Mrs. Jafferty delivers the parcel from the butcher to Adrienne Halberd, she takes all the packages out of her shopping bag and places them on the table, until she finds the correct one. The small tin can that Adrienne palms, just as Mrs. Jafferty prepares to leave, appears in front of her parcel of meat in the wide shot, but at the end of the parcel in the close-up.
When John Clarron picks up his briefcase at home, it is a light tan and quite fat. When he arrives at Adrienne's house, it is darker and thinner, but when he arrives at Cookham station it is the light tan fat briefcase again.
John Clarron delivers the tray of food and a glass of milk to Madge in the morning before he leaves for London. She does not drink it until after 7 pm (as seen by the clock on the bedside table). It would have spoiled by then.
(at 35:45) when Simon goes over to Madge's house, the patio door he opens does not have a latch on it, nor does it have a hole to receive a latch (if it was on the other door). Therefore he didn't need to "jimmy open" the door as depicted.