Looking at these pictures (and some others I took) I think I see what happened. In the "before" picture, it looks like one of the Tesla supercharger cabinets is directly behind my car. I hadn't noticed it before, but it must have been the one I was using. (This explains the "Check charger power" message I got on my phone!) The truck must have veered off the road and jumped the
over the guard rail some distance earlier, hit this cabinet head on, and pushed it through space 4B (on the driver's side of my car). It ended up where you see it in this picture.