Eroticism and death are intricately entwined. I think it is natural.
Okay, most people compare the sexual act between two living people with death. They feel that letting go while having sex and having orgasms is like dying. I do not care that for me it is just the other way round. I see death...
No, you do not have to explain it. Some people do, some do not. That's all.
I agree that necrophilia can be a fetish.
But in my case it is not. It is a preference. I prefer a dead partner to a living.
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...