The difference is that my home copy is my own work and action. The distribution, in this case, via source code, allows anyone to download that copy.
If the code snippet that downloaded infringing materials didn't exist and the user had to find the parameters themselves, that's fine. But it does exist and was included alongside a tool that makes that recording possible.
A better analogy would be like, if you had a video store that had a machine in the store that allowed people to make copies of a video tape using a duplicating machine. If someone wants to buy a duplicator for home use and use it in their home, that's one thing (though there was litigation around that too), but if you go to a store and can plug in a video tape -- and the example in the store is a copy of a Disney movie -- that's sort of what this is.
(Photocopy shops and libraries often have fairly strict rules about what kind of content can be photocopied, for what it's worth. The guy at Kinkos at 3am might not care that you're copying an entire textbook on the machine, but if you go to Office Depot in the daytime, they definitely will. Kinkos was sued and lost over a photocopy case in regards to excerpts/packets/anthologies for textbooks.)