gf drove off a curve didn't realize curve was higher so the plastic piece inside part of rear right bumper popped out
I wish I worked in the autobody department so would know how to deal with these issues. last week, I bumped into a wooden post but no scratches and bumper alignment is still perfect. I totally lucked out. Good luck. I let my gf drive my car when it was new just once and never let her touch the steering wheel again seeing how she curbs her wheels almost everytime she drops by my place.
My wife did almost the same thing to her Prius, and luckily I was able to fix it. I saw the picture where you pulled the bumper away from the body, and there is a white piece of plastic shown in the picture looks broken off, this is what the clip attaches to. It looks like yours is missing the last 6 or 7", which has been ripped off just ahead of the Phillips screw that is shown in the picture. I believe without that missing piece the clip has no where to attach to...................IMHO
I agree with John above. The same thing happened to me but the plastic part did not break. I was able to get the clip back in its slot and everything popped back in place. Whew !! It looks like you need to get the plastic piece replaced.