European Collector with Scruples, Dealer unnamed

Belgians

An unnamed Belgian dealer sold a named collector an ancient Egyptian artefact that had been stolen in the security vacuum in the aftermath of the 2011 uprising (AP 'Ancient Egypt tablet back after collector notified officials' 3rd March 2016). The object had been found by the Egyptian-Australian mission during work in the area of the king Teti cemetery, at Saqqara in 1996.

Swiss art collector Jean Claude Gandur notified Swiss authorities about the item.The general supervisor of the repatriation department at the antiquities ministry Shaaban Abdel-Gawad said Thursday that Gandur had bought the Seven Sacred Oils tablet from a Belgian antiquities dealer and had notified the authorities when he found out it was stolen.

I guess that dealer had not managed to find out how and when this item had entered the market. So why on earth did he or she add it to their stock? I think the dealer should be named so resposible collectors are alerted to the fact that this individual has had problems doing proper due diligence. How did the collector ascertain the object was stolen when the dealer (who has access to at least the same resources no doubt) had failed to do so?