This sounds like a case of typical resource guarding behavior. They don't have to grumble and growl to be guarders. Eating fast (an I refer to the speed described by the OP) is something tested for when temperament testing. The pup wants to be sure it gets all of its food. If you overfill the bowl, it will still eat it all. I have one of three like that. She is done first and is darn sure no one can get her food before her. I can take her bowl, no issues but she wants to be sure she gets all the food.

My suggestion would be to treat it as a resource guarding issue so it never goes beyond emptying her bowl fast. You don't want the grumbles to start, so be sure you always handle and can take away food and food bowl. Always add something special back to the bowl when you interrupt the meal. Even my crazed girl will back away when she sees me coming. I just may drop some Prime Rib in there!

I have dealed with this in two ways; first is to add a lot of water to the food/bowl ( helps to keep them from choking/regurgitating their meal ); or, I will scatter their food over the floor, so they can only pickup one or two kibbles at a time, takes them a lot longer to eat their meal, and no choking.