[css-scoping] should `::content` match both <content> and <shadow> insertion points?

I've been experimenting with various "inheritance" techniques using web
components, and I encountered what I consider to be unexpected behavior in
Chrome. Here's a jsbin example:
http://jsbin.com/lonugosoxo/1/edit?html,output

To summarize, I'm creating two shadow roots on an element. The younger
shadow root contains a <shadow> insertion point and the older shadow root
contains a <content> insertion point.

In the younger shadow DOM I have a <style> defined as follows:

:host::shadow ::content > * {
  border: 1px solid;
  margin: .5em;
  padding: .5em;
}

Since there is only one <content> insertion point, and since the element in
the main DOM only has one set of children, I'd expect this selector to only
match the element's children in the main DOM, but as you can see from the
example, it's also matching the <nav> element in the older shadow root (if
you look at the example, I would have expected that only the links would
have borders).

If this behavior is considered correct, I'd argue it's confusing and maybe
`::content` should have a different name, since insertion points can also
be created with a <shadow> tag. If  this behavior is incorrect, well, I
guess I'll report a bug.