Those using a Defibrillator have absolutely no liability. Defibrillators are designed to administer a carefully calculated shock which will not harm the casualty. Defibrillator settings cannot be altered so there is no liability on the First Aid responder if the casualty does not survive.
An Automated External Defibrillator will also not ‘shock’ someone if they do not need it, so it cannot cause more injury than the casualty is already in. Businesses do not need to worry about a Defibrillator accidentally shocking someone or delivering a higher charge than needed, as they have been designed for the exact scenarios they are sold for – public use by everyday people.
When a Defibrillator is used in an emergency ‘The Good Samaritan Act’ is applicable. The act acknowledges that the First Aid responder did everything within their power to revive the casualty and the loss of life is at no fault of their own.