Update, ended up hacking it up a bit, and basically grab the nodeguid from the permanant url and use that with Trevor's query above. It works, and its not idea, because its based on that url being the same for all of the download documents, which thankfully they are in this case. Hope that helps someone in the future.
{% x = QueryString.GetValue("url"); y=x.Split("/"); z=y[2]; RootDocument.AllChildren.Where("NodeGUID='" + z + "'")[0].GetValue("DocumentName") |(identity)GlobalAdministrator%}
Also, thanks for the help everyone!