He is still probably reacting toward what he's been through. All of our 7 dogs have been rescues, Our little Brutus was seen by DH thrown out the back window of a car on a heavily traveled industrial road. He did let them have a piece of his mind. Then he saw DH and basically asked to go home with him. My sister had a apso and a cat. The apso did the same thing. She would just say to him it was ok, like No No, It's Ok. They appreciate the new surroundings but never really forget the abuse. It's a scar that stays with them just the same as humans have.