In the event of a dispute, it will be up to the buyer and seller to provide as much evidence as they can to prove they are in the "right" and that the other party is in the "wrong". This may include providing video evidence of packing the box the item is being shipped in (or in the case of the buyer, of opening the box the item was shipped in). Other evidence may include photos of the item that is claimed to have been received.
This won't work if one of them is a scammer. Seller can have a studio-quality single take video of packing a $5000 widget and then ship a brick off-camera. Buyer likewise can open the package on video and "find" a brick, after previously removing the actual item.
If you ever resolved any disputes based on this type of "evidence", chances are that you helped a scammer.