Guild achievement criteria missing in API

Example:
http://eu.battle.net/api/wow/achievement/6668
says it requires criteria 19484, 19485, 19486, 19487, 19114, 19488, but when we go to
http://us.battle.net/api/wow/guild/chogall/Exodus?fields=achievements
they have the achievement but they're missing all criteria for it

Also, there are no "checked" criteria for that achievement on official Armory:
http://us.battle.net/wow/en/guild/chogall/Exodus/achievement#15079:15154:a6668

While we're on the same topic, some old guild achievements are displayed with the similar error:
http://us.battle.net/wow/en/guild/chogall/Exodus/achievement#15079:15087:a4985
achievement is complete, all bosses are killed but Nefarian isn't checked.