FEDEX and UPS have Security surveillance cameras covering every square inch of their sorting facilities. Each package has bar code and is coded throughout the process outside and through inside the sorting so they can address any quality control issues with work process flow. The ‘top people’ at the Express carrier Fox is talking to would only know the sort tracking flow of package at first review. More extensive investigation would require viewing of the surveillance cameras through journey of the package. If it’s Federal Express, it would get scanned by initial driver pick up, then again at initial FEDEX depot in NYC. Sorted and put on FEDEX plane to Memphis FEDEX Main Hub, sorted then FEDEX plane out to LA direct. Sorted at Fedex depot in LA, then put on FEDEX delivery truck.
Sounds like it was discovered tampered with at initial Depot, Memphis depot, or LA Depot.
{resumably there is also DHL... However, I would expect that DHL has a security videocamera setup that is analogous to FEDEX and UPS...
Perhaps the same cameras that were watching Epstein. If someone was pulling this off - easy enough to disable cameras.