Dealing in recently-surfaced antiquities?

Fabio Isman's report in Il Giornale dell'Arte has important implications for the International Association of Dealers in Ancient Art (IADAA). It appears that 16 objects on offer by a North American member of the IADAA in late 2010 (and some are still available) could be identified from three major dossiers of photographs derived from raids in Switzerland and Greece.

The IADAA makes its position unambiguous: "As our code of ethics makes clear, we refuse to deal in pieces, which are looted or stolen."

The IADAA's Code of Ethics states: "The members of IADAA undertake not to purchase or sell objects until they have established to the best of their ability that such objects were not stolen from excavations, architectural monuments, public institutions or private property."

Members of the IADAA "adhere to a stringent code of conduct designed to serve not only the interests of their clients but also the integrity of the objects themselves."

So, if there is such a stringent code of conduct, how has this happened? What are the full collecting histories of the objects? Was the dealer aware of the origins of the objects? Were the pieces purchased in "good faith"?

It needs to be remembered that 9 of the 16 identified items appear to have passed through the hands of the same dealer on previous occasions (since 1985 and up to 1991). Who were the sources for the pieces?

Some are designated as "ex Swiss collection" or "ex English collection". Were these private collectors?

Will the IADAA be checking that the circumstances of the 16 pieces?