Stan Jones did not see the blood which had run from the corners of Sheila's mouth, or out from her left nostril that pooled in her left eye socket - because at the time of his first visit to the scene, in particular the main bedroom, there was no blood running from the corners of her mouth, or out of one nostril, and there was no pooling of blood in her left eye socket!
I find that the blood only started to run from the corners of Sheila's mouth, and out of her nostril, once the second fatal shot had penetrated the base and roof of her mouth en route to its final resting place inside her brain, and that when Stan Jones first saw Sheila, that that second shot could not have been fired...
Hence, why he only saw one bullet wound on Sheila's neck on the very first occasion that he viewed her body!