Probably it's both. According to a number of sources, including the Guardia Finanza in Italy, the issue date of the 500 billion dollar bearer bonds was 1934. And on the Kennedy bonds (1 billion) there was an engraving of the space shuttle.
There were no such bonds issued in 1934.
The last Kennedy bearer bond was issued in 1969, 14 years before the shuttle flew.
They were, however, very high quality forgeries, as the investigating officers attested to in a number of reports. That's a pretty expensive hoax, prohibitively expensive for most counterfeiters in fact. The denominations are a clue as to what type of organization would attempt such a hoax. Such large bonds would have to pass muster with the issuing authorities. No bank would take that responsibility. Not even a porto banco would have passed on these. It must have been a nation that was responsible. A good guess would be North Korea or Iran.
Both nations have done large-scale counterfeiting before, and quite well. It's not surprising that superlative work would be done on the counterfeiting if it were done in either place, but that might also explain the errors in detail. It is unlikely that even the North Korean or Iranian governments know the issuing dates of such bonds; the engraving artist probably added the shuttle because of the association of JFK with NASA. And that's the other way to catch counterfeiting.
If the counterfeiters use the right paper, marks, deliberate impurities, inserted threads of a specific color, but miss a small, but critical, detail, then you have a comedy of errors made from a malicious hoax. All the experts had to do in Washington was to look up the issuing dates and the artwork.
However, until the writer sees very good photographs of these pieces of paper, he'll withhold judgment. In the interim, laughter is the best response. If they'd gotten the date and the artwork right, however, this might have been the most explosive financial story in a decade. And, there's trouble still. Someone has plates of a quality nearly high enough to fool police authorities whose expertise is chasing down precisely this kind of counterfeiting. Now, they know what their mistakes were. Was that why the two couriers were so obvious, so they'd be caught to test the fakes?