First, there are many countries that use the US dollar as their currency, some of which are a very long way from the USA, and the bills used in those places very seldom find their way back to the USA -- for many reasons. If you have lived or worked in Ecuador or East Timor or Micronesia you will understand why that is.
Second, there are many other countries that accept USD as easily as their own currency (Canada and Mexico are obvious examples). Only if those particular bills showed up IN THE USA, and only if they showed up in the years immediately after the hijacking, would thay have been noticed.
Third, even if he did perish in the cold dark wilds of the Pacific Northwest that night, it would be historically interesting to know who the heck he was.