S.C. Code Ann. 44-76-40(1)
Liability: Use of an AED
An individual who, in good faith and without compensation, uses an AED will not be held legally responsible. They can be held legally responsible if acting with extreme carelessness.
Immunity from civil liability for use of automated external defibrillator
(1) Any person or entity acting in good faith and gratuitously shall be immune from civil liability for the application of an AED unless the person was grossly negligent in the application.