There's always the possibility that the Marine himself acted as the spiritual mediation that caused the spider to get down to work and web the door. Why would he be any less capable of emanating those "vibes of causation" than God? "Verily, verily, I say unto you, He that believeth on me, the works that I do shall he do also; and greater works than these shall he do". John, 14:12. Seems the Marine in this story certainly qualified...

A