Investigator Charles is studying the body of someone who died in their sleep and finds that his assistant accidentally left the body facedown while he was away. Knowing that the person, in life, slept face-up, Investigator Charles can see that the blood is pooled at their backside. What has his assistant accidentally revealed about the victim?

The victim probably died only a few hours before the assistant's accident
The victim was probably poisoned to death
The victim died at least 8 hours before the body was flipped
The victim was actually on their side when they died