It took the Iranians years to piece together the shredded documents they seized at the U.S. embassy back in 1979. Also, according to a 2011 article on the BBC News Magazine website, reassembly can now be done rather quickly using a computer program. As for reassembling a single document by hand, a 2009 article at the Slate website says that on Good Morning America in 2002, a FBI agent reassembled a shredded dictionary page in about an hour. Of course, the idea that Liam would have a suitable computer program or the skill, time, and patience to manually assemble documents is more than a stretch. It's another example of the fantasy plot devices that Days writers are so famous (or notorious) for.