Terri was bothered by the fact that the parents were going to disconnect the respirator. That means the conversation must have occurred prior to 1976.
According to Terri's friend's testimony, Terri was using the present tense, not the past tense. Terri was not commenting about the respirator already being disconnected -- just the fact that the parents were considering it.
Comprende?
That fact can spin both ways. Even after the respirator is removed (no harm, no foul), a person can still express disgust that the action was taken, because the actor was intending harm. Comprende?