No airplane at that altitude will not stall doing what they did. Who cares how the trim works with competent pilots. Remember it is aviate, navigate and communicate. That is the way it has always been. They didn't aviate.
By the way aviating doesn't mean follow a flight director. Also you need to be able to ignore warnings to aviate properly, just get it under control. If that is difficult for you, find another profession.
I sadly think Airbus has convinced pilots that they are protected so they can not stall. Why would this PF have kept pulling up if he was a normal pilot?