Re: The little man who wasn't there
"But of course I'm sure they've thought of that."
Yes, they have. Because they know what they are doing, and have decades of experience with this thing. Some of them will have produced the factoid you are quoting.
"A neutrino, or in this case an antineutrino, has a 50% chance of making it through half a light-year of solid lead."
But there's loads of them.