During the opening credits, St. Ives passes the same white RV parked in a driveway twice.
When they're shooting at St. Ives in the "bulletproof" car, part of the driver's side window is completely blown out.
At the drive-in, a western is being shown. The same stampede sequence loops over and over, sometimes even in the same shot.
The mechanic uses a Smith & Wesson model 76 sub-machine gun to test the bulletproof car. He fires far more than the maximum 36 rounds in the largest magazine the weapon uses. Plus, he stands just ahead of the left front fender of the car, but bullets are shown striking both sides of the vehicle. And the holes made in the sheet-metal are far larger than those that would have been made from the 9mm rounds this gun uses.
When Charlie drives St. Ives home from the hospital, the same street pattern repeats itself. A store sign for "Newman's" goes by several times.
$4M in $100 bills would require 40,000 $100 bills weighing 88 pounds or about the equivalent of 17.5 reams of 8.5 x 11" copy paper, and taking up as much volume. The designer briefcase is way to small to carry all that money.
When Janet drives away from Procane's house in the yellow van, shadows of equipment stands and the boom microphone are visible on the side of the vehicle, along with reflections of a bank of lights.
About 10 minutes in when St Ives is is interrogated at a precinct a microphone is visible at the top of the screen.