Topic: Expired fragment, still get Cache hit

I'm trying to cache xml output of the following controller/action:

I can get the output to cache, but when I sweep, clear, or delete the .cache file I'm still getting a cache hit.

I see the following in my logs:

Expired fragment: views/localhost:3000/directory/tags
Cached fragment hit: views/localhost:3000/directory/tags

Any ideas why this would happen? This is all on my dev box.