Does Zegzula need to be a tax expert to establish that he believes that dentistry is not subject to income tax laws?

Zegzula has not shown that this case involved any complex issues of tax law. A tax expert was not necessary to establish his defense that he believed in good faith that dentists are not subject to income tax laws. There was no prejudice as required by United States v. Brewer, 783 F.2d 841, 842-43 (9th Cir.), cert. denied, 479 U.S. 831 (1986), and the court did not abuse its discretion. See United States v. Becerra, 992 F.2d 960, 965 (9th Cir. 1993).