I didn't say it was Khaz Algar, but that the facility is IN Khaz Algar.. or somewhere below ground near Khaz Algar.
We don't have any information on what it could be.. and while people say it could be the facility under the Tomb of Sargeras, they don't explicitly say Uldaz. If that part of the instance WAS Uldaz, then the item (The Infinite Hand) would've responded to it and the Infinite Domain ability would've proc'd.