Yup! I do peak in the ladies occasionally. Wasn't my place to respond there so I omited to.
Dogs have a special sense. My previous lab Alex, never slept in our bed. I was at the hunting cabin one year and came down with something, and just felt miserable so I laid down. Alex jumped into bed and cuddled against my back. That was the first and only time he had ever done that. My present lab loves everyone and would lick you to death, but I am sure that should something similar to your incident occur, she would be all teeth as well.
I believe that special sense is smell, she smelt fear via emited pheromones or one of them mones etc... and knew exactly what to do. Animals aren't given enough credit IMO, they are more intelligent than we think. I know I don't need to explain that to you. Hershey's body language is well second to none and she conveys messages loud and clear with her eyes. Too funny at times, especially when she's POed at daddy.