mdlevine, the tax will be paid.
an interesting story thats more related to ma’aser, but fits in here.
Someone who was deep in debt, decided to try to pay up quicker by not giving ma’aser. He noticed a pattern that since he stopped giving ma’aser he’d gotten several tickets for small things. He became especially careful with ma’aser and it stopped. One day soon after, he got paid and didn’t have a chance to give the ma’aser. The money remained untouched for a while. He got pulled over, and immediately realized what had happened. While he was in his car, waiting for the officer to check his license etc, he called someone and asked them to put 10% of the amount into tzedakah for him. the cop returned soon after with only a warning. No ticket.
Whether with tax, ma’aser etc, no one will make any money that they were not supposed to get anyway. There is no “cheating” Hashem.