Christie's and their Blood Antiquity Line

From Fox News:

Sung-Hee Kim, communications liaison at Christie’s, who said to date, the auction and art house has not encountered any such items [looted by ISIL in Syria and Iraq] [...] According to Kim, Christie’s has a policy of not accepting items for sale without a legitimate signed title confirmation. In addition, they require provenance pre-dating the year 2000 as well as pre-dating any periods of significant conflict.

What is a "a legitimate signed title confirmation" and how is it differentiated by Christie's from "an illegitimate signed title confirmation"? I really would like to know. Now the antiquities legislation of Syria and Iraq is a complicated matter, going back as it does to Ottoman-period laws, but what is certain is that items excavated and exported from both territories merely before 2000 without following proper procedure are technically not licit antiquities, but obviously Christie's is prepared to bend the definitions a bit and treat them as if they were.  What is a "significant conflict"? How many deaths and displacements are needed before Christie's considers the "Blood Antiquities" Line has been crossed? I think we deserve an answer.