[Rutles4Ever]

Unless the items were placed on board after the flight landed and before the maintenance folks found them... So the plane landed, and a passenger went to the bathroom and created these packages out of thin air before leaving? I would think that the packages would have to get through some security point no matter when they're found...

[berkeleybeej]

and a passenger went to the bathroom and created these packages out of thin air before leaving?

It doesn't necessarily have to be a passenger...could be ground crew personnel.

But more will be revealed in the fullness of time...