Before being hit, Robinson's hat instantly vanishes from his head.
At 1:04:25 Brother Superior's right arm is in his lap. When it cuts to the reverse angle, his right hand is placed on Brother Orchid's shoulder.
When the two hoods approach Clarence outside the sanatorium entrance Clarence puts one hand on the shoulders of each man. In the next shot one of them is standing back out of reach.
At 1:25:55 As Brother Orchid enters the monastery, he holds his hat with both hands. When it cuts to a medium shot, he is holding it with one.
The leader of a Monastery is called an Abbot not Brother Superior.
However a Mother Superior is a nun who is in charge of the other nuns in a convent.
When John Sarto goes to get Willie the Knife (Allen Jenkins) released from the Sanatorium, the sign of the institution is misspelt "Pattonsville Private Sanitarium".
This, however, is not a Goof; both are legitimate words, and they are interchangeable.
As Jack Buck and John Sarto fight, Humphrey Bogart fails to pull a punch and actually hits Edward G. Robinson in the face.
When Johnny is in the monastery and sees the newspaper article about Flo's engagement to Clarence, the entire article is shown on-screen. When Johnny reads the story aloud, he adds in the sentence "Never in my life, Miss Addams told reporters, have I been so thrilled and happy." That sentence did not appear in the news article.
Brother Superior places his hand from his waist onto John Sarto's shoulders so fast that the movement can't be seen.
The shadow/reflection of the camera and cameraman are visible on the shiny table in the gangsters' boardroom.
When Edward G. Robinson returns to Ann Sothern's former rooming house and the landlady tell him she's moved, the boom mic is visible in the door's glass panel.
Crisp turns the steering wheel to stop on the left side of the street.