Limbsurfer,
That choker was supplied by the crane rental company. I'm sure if they didn't trust it to lift objects off of a house, they wouldn't use it. I personally don't like using them. We prefer an eye & eye choker with a screw pin shackle, when we use wire rope.
Mark,
I didn't notice any lawn irrigation systems at that residence, but alot of them do have it. Just because I didn't see it doesn't mean there wasn't one. As you can see in the pics, the lawn was long. More than likely there was one. I did notice that the base of the tree was in a low area. Water could have collected at the base of the tree.