You're forgetting something vital, voynich. For my part, you have to take the holistic view and balance the DNA against everything else to reach a conclusion. Let me lay this on you: in order to prove that there was a primary transfer, you have to prove that someone else was there that night, which to date, cannot be done.
I have something even better. In the state of Maine, there's a man named Dennis Dechaine serving a life service for murder. In 1988, he kidnapped, assaulted and murdered a young girl named Sarah Cherry. Despite the fact that a mountain of evidence, including his own confessions earned him that sentence, there's a movement to free him. The "evidence?" DNA on Sarah that doesn't match his. Whoever killed Sarah (I'm convinced it was Dechaine), stripped her,sexually assaulted her with sticks (which were still inside her), stabbed her with a very small knife and strangled her with a rope. Now, you'd THINK that Dechaine's DNA would be all over her, right? Especially since DNA testing hadn't really come into its own yet and Dechaine wouldn't be careful about leaving it. Well, if it is, I've certainly heard nothing of it! The only DNA that's mentioned is the DNA that didn't match his.
Isn't that odd?
We don't know it DIDN'T. I saw a demonstration on TV where the tech said that the machine filters out any DNA that is not a match to the sample you're looking to match. They said it, not me.
Actually, no. And again, it goes back to the holistic view: OJ's crime scene DNA was blood. It was not degraded or miniscule. And he had a cut on his hand. Now, given everything else, wouldn't you say it was likely that he accidentally cut himself during his killing frenzy?