(a) Section 324.099(b)(2) does not impose a tax on:
(1) an employee of the United States government conducting official business in the district; or
(2) a person who occupies a lodging facility or campground in the district if the person has evacuated from the person's home due to an emergency and the state has temporarily suspended collection of the state hotel occupancy tax.
(b) The district may not tax a transaction between a person and an interest operated by:
(1) the United States in the district; or
(2) a state park in the district.