I believe so, yes. I even commented about there not being a bolt release and you cant lock it back without a mag in it and the guy at the gun store said he didnt like that part as well. And I know this guy and he actually knows his ****. But I didnt actually lock it back with a mag in it and then remove the mag to see if it closed so I cant say for 100% sure.
Was the one you saw a new one (was it a takedown), or one of the originals? The originals from some quick reading, don't hold open except with an empty mag.