The Austrian National Analysis Center (NAC) examined the 493 banknotes Hölzen and B. had in their possession. Of those notes, 295 were originally $1 bills. Counterfeiters increased the face value of the bills to $1 million, simply by adding six zeros. The counterfeiting was done "very expensively and professionally," say the specialists.
The men - one of whom is an attorney - claim that they were not trying to pass counterfeit money because they thought the bills were genuine. They now suspect that they may have been victims of a scam.
Link.
At least I'm assuming they weren't just given it for free.
I'm curious to know how you get your hands on $500 million in CASH and not at least suspect shady dealings.
Sure, but could you tell if German currency is legit just by looking at it? They are either ignorant of knowing what the bill actually was supposed to look like, or they are feigning ignorance. It's true, Europeans can know just as little about the US as is vice versa.