The only way I could explain that there are no signs is that it was reflex death. I don't think this happens usually in autoerotic accidents. If this was real strangulation, it would be hypercapnic and one would see that he had fought against his death. Also there would be petechia and his face would be swollen. If at all, he died not because of lack of oxygen but because the blood flow to his brain was stopped. His death would in all probability not have been so "beautiful" as he is on the pictures. So I agree, it's a fake.