Google irregularity

There's something strange hidden in this BBC report on Google's alleged changes to search result rankings.
Basically, search Google for 'shelving' and you get one set of results. But search for 'shelving -anything', where 'anything' is indeed anything, and you get a completely different (but in fact much better) set of results.
Also, I can't find any words other than 'shelving' for which this happens.