Corrected entry: In the shot that had the camera peering down into the bag of cash, you can clearly see that the money is motion-picture-use money--it says so on the money. This is a particularly confusing faux pas because it is supposed to be real money, but if you see that it's motion-picture-use money, that changes the plot.
Correction: Exactly. One: the production was running out of money, so to overcome their problem, they use fake money to bribe the guy. Two: the 'good' guy is bribed to drop the charges, but they trick him by using fake money.