I have a feeling that if God had decided to strike your grandfather's barn, He wouldn't have drawn up short at the sight of a metal rod stuck there, thinking, "Dang! The crafty old fellow outsmarted Me this time!" but more along the lines of "Screw physics--the barn's goin' down!"
My own experience has convinced me that it's not very smart to get into a battle of wits with Omniscience.
Our family had a great laugh over this!