The Advance Guard never got the chance to set out, because as soon as Harry and Hermione showed up at the Burrow the Weasley's informed everyone else. Moody demanded to know what she'd done and how she'd done it, but Hermione gave only nonsense answers, such as, "we were carried by an army of pixies" or "the moles dug us a tunnel". There was little he could do to her and they both knew it, and as far as Moody was concerned she hadn't actually done anything wrong.