I've just tested this again, and it seems to only happen when I type the query directly from my Chrome url bar (I'm using Google UK if that makes a difference). Same on Incognito. I get the "Copyright" page at https://www.openstreetmap.org/copyright and NO LINK to the homepage anywhere on the front page of results, which seems nuts.

https://s33.postimg.org/7iaf0z47j/Screenshot_from_2016_05_25...

But copy-pasting the resulting URL into Tor results in a 403 page.

Does anyone have a reasonable suggestion for this behaviour?