Tim_Beard,
The dot is a styling artifact, the result of a dropdown menu with zero elements in it. That Actions dropdown exists in the toolbar because there might be some action you could take based on the item you have selected in the tree- if there was, you'd see the available actions when you clicked the dropdown. That toolbar doesn't necessarily know which items you'll have underneath it, hence the presence of an Actions dropdown that (in this circumstance) has no items. No actions are unavailable to you, there just aren't actions for that item.
As for why the styling artifact shows up as a little dot instead of something like "no actions available", that I don't have as good an answer for. More recent CUI elements lack it, so I suspect it's likely to disappear as old elements are phased out in favour of new, but I don't have any particular timeline on that.
Skyler C.
