As I much as I also believe that, there is no hard evidence (that we know of) that he didn't kill himself. I think that's why it's in that section. The suspiciousness of it is through the roof, but we can't prove it.
Right, the chart is far from perfect, but they just grouped them both under the "we have questions" section. We have lots of unresolved questions about Epstein's death, we have lots of unresolved questions about UFO sightings.