When Vincent is at Madge's apartment, at one point, Madge sits on top of a pillow on the floor right in front of Vincent. A couple minutes later, Vincent gets up. When the camera turns back to Madge, she is now sitting on the couch which was about 3 feet behind her previously.
When Parry first hops on the cable car, a long shot shows it to be car #507 in Union Square. A quick insert shot of Bogart on the cable car is quickly followed by a further long shot showing the car to now be #508. Then it appears to be #506 entering the turntable. In the next shot the car is #520. Then it's back to #506 in the turnaround, and a closer shot shows it to be #520 again. The final shot on the turnaround shows it to be #506.
Dr. Coley says he's going to leave Vincent's nose alone but do work on his eyes. The bandages cover his nose, as if he's had a nose job, and clearly indicates no work was done on the skin around his eyes.
Shortly after Vincent arrives at George's apartment he sits down. (During this point of the movie, things are seen from Vincent's point of view.) When George steps over to the window, the night stand is at Vincent's 10 o'clock position. Immediately after George says he can give Vincent a spare house key, the nightstand is now at Vincent's 12 o'clock position.
At the start of the film when the truck is shown driving with a load of barrels, there's a solo barrel placed on the edge of the tailgate. But on the following cut as the truck passes a curve, that barrel is not shown. Then on the next cut after that, the barrel reappears.
While Vincent Parry's face is changed by plastic surgery, his recognizable voice is never mentioned. However, Vincent encounters very few people after the surgery and those would have been unlikely to know him by his voice.
Dr. Coley tells Vincent to sleep flat on his back, but when Irene enters the bedroom where he's sleeping, it's clear he slept with a pillow. However, all the doctor meant by 'flat on your back' is that Vincent should not sleep on his side or his belly.
After Parry's bandages are removed, there are no stitches or bruises, nor is there the sort of facial swelling that always results from plastic surgery.
Someone who had truly been in a hurry to flee would have purchased the two extra tickets that were required for the bus to leave rather than wait for others to buy them.
In one of the views of the Golden Gate Bridge, the water does not move at all, revealing that the background is a still frame.
After the surgery, the doctor tells the bandaged Parry that he will look older than before when he sees his new face, but when Bogey's face is revealed, he looks younger than the Vincent Parry shown earlier on the front page of the newspaper.
When Vincent is sitting at an open-air table near the ocean in the Peruvian cafe, there is a lit wax candle on his table. However, the movement of the water indicates there is a strong ocean breeze therefore since the candle is not covered, the flame would not be able to stay on.
Both Madge an Bob associate hearing Irene's stereo as her having company. It is reasonable for someone to listen to their stereo by themselves.
The Powell Street cable line does not run anywhere near Telegraph Hill where Parry supposedly boards a passing car that takes him downtown.
In the diner, a sign on the wall for the ham special says it includes "potatoes - salad - drink - and 'desert.'" (not 'dessert').
Vince tells Irene, with certainty, that Madge "accidentally" fell out the window, but this is NOT supported by what Vince could have known.. Madge went behind the drape, hidden from Vince's view, the window is heard breaking, and she fell (or jumped) out. Vince did not see, nor could he have known how or why Madge fell - whether it was accidental or a deliberate act of suicide. He did not see her fall (or jump} and reached his conclusion as an assumption without having witnessed what happened, directly. (Another plausible possibility, that Madge committed suicide, is consistent with earlier plot developments and revelations).. Vince's conclusion is, therefore, speculation, not fact, as he presents it to Irene..