Wow, yeah, same two redirects for that PDF link. Geez. It'd sure be interesting to know the full cause here, otherwise it really destroys a lot of trust in the tool.

Edit: It sure does seem to be a PDF problem, these were both NYT things, but I tried a CCC talk page that had a slides link and sure enough, same behavior.

    https://archive.ph/o/n5qxb/https://fahrplan.events.ccc.de/congress/2015/Fahrplan/system/event_attachments/attachments/000/002/825/original/32c3-slides.pdf