I've never seen The Holy Grail, so I can't comment.
However - in the sequence where the mountain-top beacons are being lit, there's a helicopter shot where the bonfire swings right through down-sun of the camera aircraft. I swore the shadow of the a/c should have passed through the shot, but I failed to catch it, twice. Anyone see it?
Quite apart from that, a monumental achievement in cinema for which Peter Jackson deserves three oscars, three BAFTAs, a couple of Grammies and canonisation.