My reading of the link you posted above is that they dropped the mail-fraud and contempt charges stemming from him continuing to file legal documents warning of "dispute" over the properties the government seized (to make the properties undesirable to potential buyers and thus screw the taxpayers) during his prosecution, wherein he and his wife *were* found guilty of (quite a few counts of) structuring, tax evasion, etc. As far as I can tell, the original charges have not been dropped.
Did the government prosecute them for appearing to purposefully avoid reporting on large withdrawals so they could further hide not paying taxes on the wages paid to their employees (argued to be independent contractors, but there are reasons you can't just claim that when the IRS comes knocking)? Or for being a creationist telling the truth, because the government's just a pawn of atheist, evolutionist, neo-Nazis? You decide.
Did the government prosecute him for filing Notice of Pending Suit from prison, after the case seizing his properties had concluded, as a form of harassment, trying to prevent the government from doing what the jury of peers agreed they could do, thus the contempt charge? Or were they charging him with mail fraud because filing Lis Pendens in court is a form of freedom of speech the government just cannot allow, because it might allow creationist truth to get out? You decide.