I guess that's the point: it's gotta hurt more than you could imagine before it's torture.
I think from the context of the memos it is clear the organ they're referring to is the heart. It follows therefore, if the subject's heart stops, which can be relatively easy to determine in the field, the abuser has a clear indication he or she has gone a bit too far and should back up and trying some form of abuse less torturous.
Given that we appear to have an endless supply both domestic and foreign who if not should definitely could be potential subjects, over time the abusers will refine their techniques sufficiently to get to the point of heart stoppage without actually crossing it.
Operationally, this "bright line" indicator is the most reliable guide.
and, if you would be kind enough to inform lazy me, what are the rules for what happens when it becomes clear the torturer has crossed even those lenient lines? Is a written apology in order, to be placed in the deceased coffin as he is buried deep in the desert under the cover of darkness?
In addition to being disgusting and useless, the "death or organ failure" line is really really crappy legal analysis.
See this post:
http://obsidianwings.blogs.com/obsidian_wings/2004/06/another_torture.html
(or click my name)
Isn't the "level [of pain] that would ordinarily be associated with ... death" just ZERO. That's one of the main things about being dead -- at that point, you're an inanimate object which, famously, isn't capable of sensory perception. WTF?
The pain associated with death the state may well be zero, but the pain associated with death the process may be great. So many ambiguities in English.