I have not found much information as to their experimental setup, nor how they were able to pace neutrinos against photons to get the speed difference, but based on past experience with assumptions in physics experiments, I can make an educated guess as to what is going on.
First, consider that they are measuring "velocity", not scalar speed. And they are unaware of both the progression of the natural reference system and temporal motion, which is what particles and atoms are made of.
There is one big difference between a neutrino and a photon: the neutrino is a ROTATION, which has "area" to it, whereas the photon is a linear vibration--no area. Having area creates resistance to motion (or at least how we would interpret it). Examine any element. The larger the temporal displacement, the more resistance to motion it has... a lot easier to pick up a block of aluminum than of lead. One can consider the DENSITY of the material to be how much resistance the structure is putting up to moving WITH the progression.
Photons don't move relative to the progression of the natural reference system. The structure of neutrinos also allows them to be carried by the progression at the speed of light (free dimension), but the temporal rotation of the particle will slow them down, ever so slightly. Neutrinos SHOULD have a velocity just a tiny bit under the speed of light, as we're only dealing with a single unit of temporal displacement.
The big question now is: what are they actually measuring?
Conventional science does not know of the existence of UNCHARGED particles, so they only measure the charged ones. Neutrinos are unusual in the fact that they have zero net motion, 1/2-1/2-(1) = 0, which is why they can pass through EITHER space or time. The charge on a neutrino is in time, so if a charged neutrino enters another time structure, like the atoms in the rocks of a mountain, it will get stuck there as the relation of time to time is NOT motion. (Charged neutrinos build isotopic mass, per BPOM). So they are NOT measuring MATERIAL neutrinos.
The basic difference between the material and cosmic is that material particles and atoms move at sub-light speed, whereas cosmic particles and atoms move at supra-light speed. If they are actually measuring supra-light speeds, there is only one thing it can be in the RS--cosmic matter.
Consider now the COSMIC neutrino, (1/2)-(1/2)-1, with the charge in SPACE. Space to time constitutes motion, so they fly right through matter. BUT... the rotation of cosmic particles are in SPACE, not time, so the particle would move just under the speed of light IN THE COSMIC SECTOR, and the RECIPROCAL would be measured here in the material sector--cosmic neutrinos would move just slightly FASTER than light, due to its spatial rotation. And it is just another "rotating unit of space", like the electron is, which makes it ultimately measurable as well as unstoppable.
From what I've read, my conclusion is that they are measuring C-neutrinos, which appear to move slightly faster than light because of the spatial rotation they are composed of (the particle is covering "more space" in the SAME amount of clock time than a photon would--faster, whereas the M-neutrino's temporal rotation would take "more time" across the same distance--slower).
I would consider their results valid; except they don't know they are measuring an "anti-particle."