The pair claimed the bonds had been sent by the American government to Chinese nationalist leader Chiang Kai-Shek during World War II, but that the plane carrying them had crashed in a Filipino jungle and the bonds were lost until Slamaj stumbled upon the crash site in 2001. Now, there were a few holes in this story. For starters, "Load all the money in the world onto a single plane and fly it over enemy territory" seems like a risky financial transaction, even by 1940s standards. The Lend-Lease program didn't see the US shove the complete contents of Fort Knox into a rickety van and try to drive it to Moscow by way of Berlin. Also, we're pretty sure the government is allowed to disregard a bond certificate if it's soaked in pilot blood and 60 years of tarsier urine.
But no one needed to ponder those issues, because the forgers made a simpler mistake -- they forgot to spellcheck. When the pair tried to cash $25 million in Toronto, officers noticed the bonds read "dollar" instead of "dollars." They also contained zip codes, despite supposedly being printed decades before those were introduced. Oh, and further testing revealed they had been printed on an inkjet printer, which isn't exactly period accurate. They couldn't have been less convincing if they were scrawled in crayon on the back of old GameStop receipts.
Meanwhile, a lawyer independently called the police after the men told him they had $2.5 trillion in bonds because, again, that's obviously insane. As a bit of bonus idiocy, Slamaj tried to bluff his way into Halksworth's safety deposit box, presumably to destroy evidence. But the cops had already beaten him to the vault and were actually in the next room, listening to the whole thing play out. Both trillionaires were quickly sentenced to prison, proving that there's justice for the super-rich after all.