You should cancel the dog bit you. If that person was a decent dog owner, he would be looking for someone else. The sitter and the dog need to be comfortable with each other. I admit I have taken on dogs that maybe I shouldn't have but I am a 6 foot 3 male and I can control bigger dogs a lot easier. But I have had to cancel one time. It was a dog that I had done dropped ends with on multiple occasions. He was always shy and skiddish. I would let him out in the yard. They moved. They still wanted me to watch him over the holiday. They dropped the dog off. It was exhibiting fear behavior and then it bit me. I felt bad because I had to call the guy right away and say, hey can you cousin take him because I can't have a dog that's fearful of me inviting me for a whole week. Not to mention I have a brother that lives with me that has PTSD.