"So far as the consideration of the triad is concerned and Professor Risdon's article and so forth, Dr Carey is saying that you do not necessarily need all three. If you take each of the three - subdural unsafe alone, retinal unsafe alone, and so forth, deep brain injury, lack of oxygen, that would be unsafe alone - he said two of the three would enable you to quite confidently conclude shaking. You do not need all three to have, as he put it, a good chance of being right. Of course that would not be enough for you, members of the jury."