The first hole was a rush job when the heat was on. The second hole he had more time
Maybe the bobcat wasn't available a second time or with the pressure off he didn't want to take the added risk of stealing it again.
The second site wasn't too far from a farmstead. Even buffered by the trees and barns you might notice someone digging on your land with a bobcat even if you wouldn't notice a guy with a shovel.
Good points, but then why bury him on someone's farm, especially if it is planned? Why not in the other direction, further from town? Why would someone plan a site like that? Granted, it may be that the burial sites are very close by. I still haven't pinned down where the first burial site was.