It is not just the Tennessee Governmental Tort Liability Act that has a discretionary function exception – the Federal Tort Claims Act has one, too.
This case – Navarette v. United States – discusses the exception and applies it to a case filed after a person fell off of a cliff at a Army Corps of Engineers’ park. The case includes a dissenting opinion, and thus gives you an opportunity to see two different views of the doctrine.
The opinion, released by the 9th Circuit on August 29, 2007, may be read here.