Uh, how was his turn rushed? He wiped out a tribe of sandpeople 3 years earlier and throughout the whole movie he is going back and forth in his mind over what to do. Once he betrayed Mace Windu, he knew the jedi would come after him. He had no other choice at that time but to turn. That and he was tricked into thinking Palps had the secret to cheat death. The movie is great, stop nitpicking it.