When Barnaby parks to make a call from a phone booth, he stops the car a couple yards past the corner of a building, but when he gets back in the car, his trunk is about even with the same corner.
When Mr. Jones releases the bloodhound, he uses a pair of binoculars to look at it. The view from the binoculars is from a frontal angle, which could hardly be correct, since the bloodhound would be moving away from him.
When Barnaby makes a call from a phone booth, one can see the reflection of a crew member wearing a red & white cap.
There are no roads near the spot (east of Pinyon Crest, CA) where Sierra Grocery is marked to be on the map that Barnaby studies to guess where Valerie might be found. In fact, the spot marked is on the far side of a canyon that would block any road coming from the nearest highway.