Only thing I can think of is get some polishing compound and by hand rub a 2x2 ish inch area for a minute or so. That will take a bit, but hopefully it just chemically reacted with the very surface and didn't penetrate the clear coat too deep. Test it in a small spot and see if it does anything. Best case is that you can shave a few microns of clear coat off and it will look new again...effectively that is what polishing is.
Regardless, I would talk to your neighbor about it first and it would probably be best to just file an insurance claim of some kind. **If** you both agree, it would probably be the best thing for both parties and your relationship.
Edit: Polishing compound, not rubbing compound. Rubbing is for severe oxidation and will eat through your clear coat if you aren't REALLY careful. Watch a youtube on using polishing compound, use "x X x" shapes for the scrubbing, don't do circles...puts swirls in your paint.