Perhaps the Subaru was in no wrong, and it appears the Lotus drove up under it? The Lotus certainly sits low enough to do so. Moreover, there's no bumper damage on the Subaru, save for the tailpipe, but it's a feasible idea.
I guess this must've occured at very low speeds (for a freeway at least), since there are no tire marks and it doesn't appear that the Lotus or the Impreza has any super significant damage.
