I can't say I'm fully conversant with the Italian legal system but I think it differs to the UK and USA in that there is no presumption of innocence. Also there is no "Double Jeopardy, just as there isn't any now in the UK. Interestingly I discovered that Louisiana follows the Napoleonic Code also but is alone of the other 49 states of the USA to do so.
I certainly agree that I would think that Knox's lawyers will appeal in the Italian Courts and then the European Court of Human Rights but again I'm skeptical that these have been infringed despite accusations against the Italian police. I've never run afoul of the police in Italy but where I've had contact with them they have been thoroughly civilised, intelligent and thoughtful. But them I wouldn't want to cross them, I doubt that they take any nonsense.