Alright, so I haven't actually taken the time to research this idea, but I think that there may be one error in Deathly Hallows.
STOP READING THIS IF YOU ARE NOT AT LEAST HALF WAY THROUGH DEATHLY HALLOWS
Alright, so you know how in book six the spell that Dumbledore cast on Harry broke as soon as Dumbledore died? Does that mean that all spells are broken when the wizard casting it dies?
If so, how were Moody's spells protecting 12 Grimwald Place able to work?