Explain how Status/Status Group filters work

I'm not fully understanding how these filters work in Wrike. While configuring a dashboard, I can filter based on Status as well as Status Group. What is confusing to me is that I can apply a filter on Status Group and also apply a filter for a Status that isn't in the selected Status Group, and both sets of results are returned.

For example, I'm filtering on Status Group "Active" as well as the Status "Done" (which is part of the "Completed" Status Group). What I would expect would be to have 0 results because there are no items marked as "Done" within the "Active" Status Group. Instead, it looks like each filter is applied independently and then the results are combined, or unioned.

Why do these filters work like this? Are Status and Status Group the only attributes where the filters seem to be applied using an OR gate instead of an AND gate?