Continuity mistake: Just after Sonny says, of Sal, that "that man bites" a potted plant seems to disappear then reappear from the counter. Sonny and the head cashier are moving down the counter getting the cash from each position as they go and, if you look at the signs on the counter, you can see that some shots are shown out of order; there are some shots of "Maria"'s position (no plant) interleaved with the previous position (with a plant). But the end effect is the same - appearing and disappearing plant.
Continuity mistake: In the exterior shot of Sal entering the bank, there is a car parked by the door. In the interior shot, the car is not visible behind Sal. This mistake is reversed half a minute later when Sonny enters the bank. There is no car in the exterior shot, but it can be seen in the interior one.