The perfect storm:
You're following the truck with your Segway, big pothole in the road, mail carrier texting on his phone, truck's left front tire goes right into the pothole, impact causes the rear door to pop open, the sudden jolt also causes the tape on the box to separate thus loosening the label, box tumbles out, label separates from the box while it's airborne, parcel lands in your outstretched arms. You find the nearest park bench, tear open the unlabeled package and enjoy jerky, smokes and other stuffs.
Is that what happened?