Older revisions are included in search results for taxonomy

On our faceted search landing page, we have a taxonomy facet turned on. That facet says that there are 9 items associated with a particular taxonomy term.

However, when I click on the taxonomy term, it returns 10 results. After I isolated why there was a difference in results, I found that the extra record in the search results should not have been showing up. It wasn't assigned to the taxonomy term.

Further inspection revealed that the node used to be assigned to that particular taxonomy in a previous revision, but was no longer assigned to that term. I deleted the old revision that referenced the taxonomy term and after deleting it, the node no longer showed up in the search results (as is expected).

I've marked this as critical because it breaks the core revisioning feature. I checked to see if the same behavior existed with edits to the node body, but in that case, the search results do seem to be only searching the current revision. I haven't tested other aspects, but for the moment, I'm assuming this is limited to taxonomy.