During the exciting chase on snow and icy road towards the end, the pursuing police on motorbikes are seen through the rear window of Duke's car, shooting bullets through the glass. However, during a quick series of exterior and interior cuts, the motorbikes disappear and then quickly reappear on one occasion.
At the end of the film, Duke has a lit cigarette. He makes a crack about it being cheap, then the orderly lights his cigarette again.
When Duke first meets Martin T. Fleming, the attorney says $150,000 is his fee for the armored car robbery - "take it or leave it". After the botched job (that Duke didn't participate in), Fleming said the failed job cost him $100,000.
Throughout the car chase scene squealing tires can be heard on snow covered roads.
The police track Duke down in the Adirondacks (which are in upstate New York) and stop at a gas station to ask for directions. In the background are some very rugged and jagged mountains. But the Adirondacks are very old mountains, which means these mountains should be worn and rounded. Young mountains, which are still growing, are rough and jagged. These mountains are clearly from somewhere in the Sieera Nevadas, which are still growing and are very rugged and jagged. This would make sense as the Sierras are close to the Warner Brother studios in Southern California, which look nothing like the mountains in the Eastern US.