What happened to make Sayid go from working for Ben to warning Hurley against him? I doubt Sayid ever really trusted Ben even while in his employ, but I think it's pretty obvious that something happened to change their relationship. Do you think it was Locke's visit? Did Sayid find out new information about Nadia's death that implicates Ben? Hmmm..
100%
Am I forgetting something completely obvious that happened in S4? ><