If we disregard the head blow, or believe it came
after the strangulation, I would agree with that. As it is though, I believe the head blow came first and that it caused unconsciousness before the ligature caused asphyxia.
I agree that the paintbrush was added after she had already been strangled with the cord. But since the cord caused the strangulation (IMO), I couldnt go as far as to say the entire thing was staging. I also think that where the cord was found on her neck, it didnt mask the area that is (to me) an indication of where it initially strangled her (the white line).
I think youre making an incorrect conclusion due to some misconception. Maybe going over some of the terms used would be helpful, especially for some of the people who've been here less time than you and I.
Asphyxia is generally regarded as the blockage of oxygen to the body, either by blocking the blood which carries oxygen, or by restriction of the air from which oxygen is extracted. (I have to say generally regarded because use of the word has evolved from its original intent in its Greek origin.)
Traditionally, conditions leading to asphyxia have included breathing an oxygen-deficient atmosphere or interference with the act of breathing. In that context, conditions that were thought at one time to involve airway compromise are now recognized as actually involving restriction of blood flow (
such as ligature strangulation, hanging, and throttling) and continue to be classified as asphyxia.
Asphyxia can be caused by choking, suffocation, strangulation, harmful breathing atmosphere, and certain diseases. Choking is a blockage of the airway from something like food. Suffocation is where breathing is stopped by external pressure (think: a pillow, a hand, or even a heavy weight on the chest preventing respiration -- burking, so-called from the Burke and Hare murders in Scotland). Strangulation is constriction of a body part (in this case, the neck) so as to cut off the flow of blood or air. Atmospheric asphyxia is caused from insufficient oxygen in the breathing air (think: carbon monoxide poisoning, confined space, even drowning). Think of the person who places a plastic bag over his/her head and continues breathing the same airspace until the oxygen is depleted. This too is a form of atmospheric asphyxia.
With the indications of oxygen depletion found during an autopsy, the coroner can rule the
cause of death as being asphyxia. Determination of what caused the asphyxia (whether that is drowning, manual strangulation, ligature strangulation, suffocation, carbon monoxide, etc.) is the
manner of death. So in JonBenets AR, Dr. Meyer determined that the
cause of death was asphyxia, and the
manner of death was ligature strangulation. Even though he doesnt repeat the word
ligature in his summary judgment which is the result of his examination and the results from testing (the
clinicopathological correlation) in which he summarizes the cause and manner of death, he had already stated it in the previous detailed list of injuries. And of course, he also relates that the head injuries were associated with the body responses seen from the strangulation.
(BTW, the above link has 19 sections linked on the left side that go into detail about what should be included in an AR.)