Not so reassuring.
Let's think about a plausible scenario: I run an industrial facility and am secretly dumping industrial waste into the river. My neighbors start getting sick. When they analyze their drinking water, it shows the presence of a bunch of chemicals whose most probable source is my industrial facility. My neighbors realize I'm to blame, and complain to me about dumping chemicals into the water. I say I've got no idea what they're about and those chemicals must be from somewhere else. Obviously I refuse to hand over any records from my facility.
Getting nowhere, my neighbors file a lawsuit. Then we go through a years-long series of lawsuits where I deny any wrongdoing and maybe eventually have to pay some money, although it hardly brings back everyone killed by illnesses my facility caused.
[1] https://en.wikipedia.org/wiki/Coase_theorem [2] http://www.independent.org/publications/article.asp?id=757