Except that it doesn't fly and didn't fly with three separate judges. Moreover, the tax preparer is not the target of the investigation. The tax preparer was not engaged in an unlawful activity. He was preparing tax returns.
By the way, since you have made the claim, who earned income from an unlawful activity?
The tax preparer who knowingly covered up the illegal workers by having them file with a tax ID and fake SS#, and the illegal workers that had no legal right to work in this country.