When Claw's hearse-limo pulls up to the bluff overlooking Riverton Harbor, we see the driver reach across the dashboard and switch off the ignition key, but the sound of the car's engine had already stopped a second or two earlier.
When you see the truck at the warehouse, there is no wall between the front and back and the truck is loaded full of standard gold bars in stacks, and several sacks of coins. However, when you see the overhead view of the truck as the rocket ship emerges, there is a wall between the front and back, there are no sacks, the gold bars are much smaller, and the stacks of bars occupy much less of the space than before.
A standard gold bar weighs about 27 pounds, and the amount of gold loaded into the ice cream truck would have overloaded the truck. It would have also caused problems from shifting during the high speed pursuit.
When Dr. Claw uses his weapon, time freezes all over the city of Riverton, showing several actions stopping in mid-motion and remaining in position. This means that the electronic devices in the building of the federal reserve - the gate, retina scan and the vault door - should be inoperable and impossible to function.