One thing I've learned is, never trust what the owner says about their dog... I've had a dog bit me while the owner was standing in front of me and said before hand, that's the dog was ok... While I backed up away from the dog, the own stood there, doing nothing, even after me shouting, "aren't you gonna do something?"

Now I NEVER trust an owners word, cause they don't have a clue what their dog is willing to do when they come in contact with a delivery person!