If A helps B help C commit tax fraud, which is more guilty?  I wouldn't want to be A The Accomplice, if I were in the tax return preparation business and knew what "Preparer Project" means. 

Substance over form.  The income goes on C's return.  If it is not B's income, why help them cheat?  IRS does have a Form 5754, which should have been given to the lottery when the prize was collected.  But that's only for people who aren't trying to break the law.  

But I suppose every town needs a red-light district for tax practitioners who are easy with their favors.