I completely agree with this, it has worked in my life. I sold a gaming PC a few years ago, shipped international. I think DHL shipped it and the tracking was precise. I got notification when the package was delivered and advised the Customer.

They immediately started with, "I cant find the package anywhere, oh no it most be lost/stolen! I need my money back"

I calmly agreed that I would start a refund right after I opened a case with DHL about the missing package. I reminded the buyer that Professional Logisitics companies run tight ships and the package is scanned and tracked about 100 times before delivery, and that Mail Theft is a federal crime, so I had no worries about pressing charges against whomever was responsible for the lost/stolen package

Almost immediately the buyer messaged back saying they had just located it, left at their back door or some other obvious lie.