Thanks for reporting, something very strange is happening here. I assume you can see other pages on http://www.gbif.org? I see successful downloads of the PDF in the Varnish logs, and it is served from the same place as other static assets.

Anyway, here's a copy: https://gbif.box.com/s/mi5h83nio5lnw2dfjzimar3u7dhp5loz

Or maybe it would work from our test site: http://www.gbif-uat.org/sites/default/files/documents/Advert...