If Customs opens a parcel for inspection they always put a brochure inside to explain what has happened.  They then seal the package back up with black and yellow tape stating resealed by Customs on it.

Now that you mention it, that's true. Been watching too much of USA customs shows.

OP as digi suggests perhaps the seller had some insurance or can do a direct claim with AP.

(Hate it when AP drivers think they are Darth Vader and start using parcels as light sabres)