Why not just ask the guy to fix the issue?

When I do a coating, sometimes the client has a small issue, it happens maybe once or twice per 100 coatings. I just fix it for the client. Most of the time it's either a high spot that was missed, or the client rubbed against the coating before it had dried correctly. In all cases, it's a 5 to 10 minutes work to fix it. I am sure your detailer will be happy to fix that for you.