What is the burden of proof against a defendant for tax evasion?

When a taxpayer furnishes leads which might reasonably explain his net worth bulge inconsistent with guilt, the government must investigate these leads or the trial judge should consider the taxpayer's explanations as true. Holland v. United States, 348 U.S. 121, 135-136, 75 S.Ct. 127, 99 L.Ed. 150 (1954). This leaves the burden of proof of tax evasion on the government, putting only the burden of production on the defendant. Id. at 137-139, 75 S.Ct. 127. However, if the defendant had actually expended the unreported income to pay unreported deductible expenses, he would not have had the cash on hand at the year end and his net worth would not have been increased. Thus, the defendant's claim does not tend to explain his net worth bulge.