I'm not entirely sure where that last part of your post came from, but anyway...
I don't know what it means, but the context seems to be about the fastest solvers of the week. In that case perhaps the "neutrino-free" title is a reference to a major Science story, a few years back, in which it was reported that neutrinos had apparently been measured as travelling faster than the speed of light.
So a "neutrino-free" time record would be one that's regarded as actually possible. Anyone who, say, solved the paper version of the crossword first and then entered their answers into the website version as fast as possible might record a total solving time for six crosswords of not much more than 5 minutes. Which is probably never going to happen.
Anyway, that's my guess, that it's an in-joke of some sort.
(After the initial reports of faster-than-light travel, an error was discovered in the experimental set-up that, when corrected, accounted for the apparent result.)