Patzer

The office building Gifford is driven up to at the start is on Park Avenue in Manhattan. However, in the succeeding shot of him inside the building, the street outside is not Park Avenue but another, narrower, Manhattan street.

When the new Gifford black convertible (actually the Ford X-100) is seen in the lobby of the Gifford building, the top and side windows are closed. In the next shot, they are open, and the occupant closes them, supposedly at the first drop of rain.

(at around 3 mins) When the black 1954 Lincoln pulls up in front of the "Gifford Building", there are light-colored 1954 Mercurys in front and in back of the Lincoln. In the next shot showing Ernest Gifford getting out of the car, a rear projection shot, the car in back of them is now the black 1954 Lincoln.

When Katie is looking in the Macy's windows, the street scene behind her does not change when she moves from one window to another. The same rear projection continued to play for both windows.