I think analyzing the blood pool is over-thinking it, because he was lying on his back and stabbed mostly if not entirely on the front, so there should have been a bleed pattern around his body, not a nice, neat single puddle. In other words, several pools where the blood ran from the wounds over the sides of his body. Also, if he'd been cut in the junk, the blood pattern would have been longer(and probably with a dry patch near the middle of where his back was).

So, not saying none of that wasn't possible, but I am saying that set-dressers left a crime scene bloodstain that in to way resembled what would have occurred had it happened the way it had in Hotch's flashback.

The show doesn't have many boo-boos, but that blood stain was wrong, even from what we know of what happened. A set-dresser poured a can of red Caro on the carpet, that's all.

Like you said, the show isn't overly-concerned with realism -- which also means the claim of 'no smudging of the blood stain' is also moot.