The justification afforded by Sections 9.41 and 9.43 applies to the use of a device to protect land or tangible, movable property if:
(1) the device is not designed to cause, or known by the actor to create a substantial risk of causing, death or serious bodily injury; and
(2) use of the device is reasonable under all the circumstances as the actor reasonably believes them to be when he installs the device.