Bud's guitar is larger than the case he's been carrying it in.
When Steak orders Don Proctor out of Bud's apartment, a vase is knocked off a shelf and breaks. Later, when Vickie arrives, the vase is intact and back on the shelf.
When Bud is walking across Hollywood Boulevard he drops his suitcase and his clothes fall on the street. As he bends over to pick the up, the screeching of a car's brakes can be heard, and Bud looks up in fear as the scene cuts to a close-up of the front end of a large white 1959 Cadillac coming to an abrupt stop. The next scene is a long shot of Bud picking up his clothes, but the car in front of him is a small, dark-colored English Morris Minor.