My problem is that with limited we go by what the character knows. Even if its wrong. We may know the truth, but we are lead to believe it is the truth.
With omniscient this, by definition, can't be done. So the writer can't purposefully mislead the reader.
Is that true? An omniscient narrator can dip into any head he wishes, but isn't obliged to do so. I can dip into the head of a character who is mistaken about something. Think of something like The Brothers Karamazov. That's an omniscient narrator, as I recall, and yet there is certainly some misdirection as to who committed the murder, and the reader doesn't know all along who it was.