(a) A municipality or county that employs or supervises first responders is not liable in a civil action arising from the discharge of a handgun by a first responder who is licensed to carry the handgun under Subchapter H, Chapter 411, Government Code.
(b) The discharge of a handgun by a first responder who is licensed to carry a handgun under Subchapter H, Chapter 411, Government Code, is outside the course and scope of the first responder's duties.