[ETL]

Maybe these particles are not affected by the material dielectric or refractive value, so they are effectively moving faster than photons while in the stuff?

Ok, this I'm somewhat familiar with. I've read in articles that neutrinos from distant stars can reach earth before photons due to this or a similar phenomenon. Might be that the photons take longer to escape the star.

[ETL]

I think what I just described is in regards to supernova explosions, where neutrinos reach earth before the photons do.