He in some other comments assumed that middleeastern ancestry in jews were around 35-40%, while rest was european. A significant amount of that euro would been south italian/island greek shifted, as most of Italy around the time jews went there, from north to south, but not majority of their euro ancestry, as jews would likely recieved different kind of euro ancestry in middleeast.
He's not 100% what exactly the ancestry of jews is, just that they arent 50% north italian(since most of Italy was rather south italian, albeit somewhat more island-greek shifted), most of their S euro ancestry doesnt come from Italy and theyre around 1/3 middleeastern, not 50%(despite almost all of their haplogroups being of jewish origins).