It looks like there's an inconsistency when exporting to CSV via the the web interface. Say I'm looking at songs released in 1989 in the classic-rock/classic-rock-song-list table from the Five Thirty Eight data. The JSON and CSV export links at the top of the page both give me filtered data using Release+Year__exact=1989 in the URL. In the Advanced export tab, though, the CSV option gives me the whole data set, while the JSON options preserve the query.

It may be that this is intended behaviour related to the streaming CSV stuff discussed here, but if that's the case then I think it should be a little clearer.