Dan Marotta wrote:

When a pilot collides with a ground obstruction it's his fault.

You would think so.
We have a local reservoir that is surrounded by a scenic network of trails.
The trails are very popular with hikers and mountain bikers. There are several large metal gates here and there to keep out motor vehicles. About 3 or 4 years ago a women rode her mountain bike right into one of these large, obvious metal gates and was injured. She sued the town for a million dollars and WON !!
So given this "prior ruling" feel free to fly into any large fixed object and if you survive, sue the owner of it.