Well, my mother told me my oldest brother had a bad dream, and when he woke up, something scratched him and it was bleeding. It was two days ago, when I was sleeping.
I guess most people have bad dreams sometimes, and I guess scratches could easily be from furnature. I have a very low blood pressure for example, so in the morning and sometimes when I stand up from sitting or lying down, I have to do it slowly or I may faint, because my brain doesn't get enough oxygen while my body is adapting to the standing position. I fainted one day after I woke up and stood up quickly, and hit a wooden table at my bed. I have no reason to think that was what happened to him, but this was just an example of what could cause scratch marks.
Something scratched him when he woke up. I assume he must know what scratched him if he knew it scratched him when he woke up and not while he was sleeping?
Claw scratches. Do you have any animals? Maybe it wasn't claws? We humans like to see patterns, like faces in smoke or all sorts of things. We like to give coincidences purpose, but many forget to think about how many times unlikely coindicences don't happen. I'm not saying that I know this is what happened to your family, as I simply don't know enough about it.