What can happen to me after my friend’s dog bit someone while with me?

My friends were separating and couldn't take their dog at either place they were staying. I helped them out and took the dog posted it online for free to a good home telling them I didn't know much about the dog just that she was loving and hyper but I couldn't keep her because my German shepherd didn't get along. Anyway, a girl called who wanted the dog, said she would train the dog and she was not worried about anything. I told her I didn't know anything about her other than she was starving for affection and love that she had been alone for a little while. I explained all I knew about the dog because she wasn't my dog. They met up with me at the state fairgrounds where the dog jumped up and scratched the girl. Then the father walked over and bent down to see the dog then the dog jumped and tried to bite him. We both said I don’t know about this then the guy sat down right in front of the dog and that's when the dog bit him. The guy smelled like a bar. He told to us not to worry about it. Now, I got attorney papers in the mail. I don't know what to do here.