Occasionally, postal employees will mark a parcel as delivered while the package is still on their truck. On some occasions, the package can even be delivered up to 2 days after the package is marked "delivered" on the tracking website.
Please also beware that mail thieves do take advantage of any opportunity they can. If you are worried that your package may get stolen, sometimes it is best to have your packages held at the Post Office. This can usually be requested by simply calling your local postal office and providing them with your name and address.
Once your package is marked as delivered by USPS, Miss A is no longer held responsible for any lost, stolen, or missing goods.