Yes.

Polygons consist of one outer ring and zero or more inner rings. In ol3 the first ring is assumed to be outer ring, but the order of the rings in the KML file is unknown. The KML parser parses the rings as follows:

1. It initialises an array of rings with as an array with one element: `[null]`.
2. When it finds an `outerBoundaryIs`, it *replaces* the first element in the array with this ring.
3. When if finds an `innerBoundaryIs`, it *pushes* the ring onto the end of the way.

This way, after parsing is complete, the outer ring will always be the first element in the array and the inner rings will follow.