I was a little disappointed by Arya's escape also, not being the same as the book - and I'm not one of those crazy book purists who obsesses over the color of horses etc - however the last episode this season is titled
Valar Morghulis so at least we know there will be more Jaquen, so there's still room for the possibility that in some way or form "Weasel Soup" could still possibly happen.