When you think about it, its this very thing that made Sopranos like an open ended book, rather than a linear (Told about every little detail) tv programme. Barry Haydu is just as much a prop to the show as pie-o-my or a chair around the soprano family table. Does it really matter whether Ralphie killed the horse?? Or was it a bigger issue that Tony still had a grudge against Ralph for smashing that poor girls head in. What im saying is the horse (being the prop) allowed Tony an oppertunity to get rid of Ralph. Just as the chair allows him to sit and eat his meal. Didn't matter if he was telling the truth or not!