Well this is conjecture on my part but I think the lawsuit would be about apportioning blame to anybody who had any capacity to pay. The argument would be that negligence on the part of the controller contributed to the accident, sort of like if you are driving 50 on a 45 posted road and somebody pulls out in front of you from a driveway you might be considered to be partially responsible for the accident as you were speeding. As to the claim of negligence because the controller didn't warn the pilot that there were obstacles I think it is all in how you phrase it and the theater of the courtroom. From a laypersons perspective it could be confusing I guess. The other thing is that there is the old fact that often settling is cheaper than winning if you are the defendant. I don't know if that applies in a case against the government but against the manufacture of the airplane, (why no radar altimeter or air bags??????), I think it often does.
