I admit that I cannot recall if I ever have seen his legs to see if the blood went that far.
But it is evident to me that he then fell to his back quickly because the blood on the chest ran down the sides of the chest.
It also says that he was moved or moved himself after falling to his back because the blood goes down the sides of his chest and stops and there is no blood line in the carpeting. The photograph of him lying on his back does not show him where he first fell. But it is very possible that Darin or the medical people moved him.
The blood stain on his chest does not look to be so great but one can see that it has been diluted and wiped away. But even if it has been mostly wiped off the evidence of a wash of blood down the chest is still there to be seen.
For myself I cannot imagine why the prosecution said that he was stabbed as he lay sleeping. To me an amateur can see that is not what was the case.
I have to edit as I forgot to say this is my opinion.