I’ve actually had a package delivered light.

I ordered two gas struts for my car, the corner of the package had clearly gotten damaged during handling and I only had one gas strut.

I have a friend who works at a distribution center for one of the big private carriers. He says that packages get ripped open on the automated conveyors and lose their contents all the time.

In that case I would accept the return and file an insurance claim. If that buyer is doing that enough then the insurance underwriter will come after them and you definitely don’t want an insurance company on your ass.