Okay, that makes sense. I was not aware of any mechanism by which the black hole would lose its charge, which would greatly increase its likelihood of passing through the a body such as the earth or sun entirely. On reviewing the paper further though, I note that they state that there is no known consistent set of physical laws that would lead the black hole to lose its charge but not release Hawking radiation, so even without the analysis of whether the particles should be able to pass through white dwarfs or neutron stars, I would be inclined to assign quite a low probability that such a consistent set of laws exists and is actually true, although not necessarily as low as one in a million.

Of course, I didn't have that data until reading the arguments on why such a set of laws should still not lead to the LHC being destructive, so it was never a major factor in my probability assessment that the LHC would be dangerous, but it makes sense that physicists who were aware of the principles involved would afford the proposition an extremely low probability.