It's ad hoc, but so is all maths, and all reasoning.
A man with a paper cut is at D=0.9999 or more. You probably have more noise from variations in sleep or eating or colds. But people don't end up at D=0.17 just randomly. El-Masri was in danger of dying. The fellow was actually tortured.
There's also no censorship in the example of the paper cut. It also isn't possible to infer much from a something like that E[D|some positive condition]=0.9999, so even if there were censorship your example with a small scratch doesn't allow the sort of argument I gave in my previous comment. My previous comment specifically relies that you have a censored sample D~P(D|something that you'd expect would make D large) and then finding that this D is small.
Still, I think there's a point to this statistical reasoning: Assange could have made it at the time, and been correct, and thus we have a strong argument for his duty to act under Icelandic law.
This is not a real thing, it's just something you made up. You can see this obviously if you transfer this to another domain. For example, if I get a paper cut at work do you think that means I'm partially dead? Do you think that singular example of a paper cut means "we can be fairly sure" that "a bunch" of my coworkers have died from paper cuts?