There is so much wrong with this crap. I can't even begin to explain.

@ForgedReality. I am not going to go knee deep into this. But I think you have misunderstood a few things. First, dispersion or the index of refraction of many materials is frequency dependent. Ironically, my graduate research focused extensively on this! In it's simplest form, the dispersion relation is (w/k)^2 = (c/n)^2. That means that the group velocity is limited by c. So in a medium where the refractive index is nonzero the speed of light is less than c. Frequency dependence further complicates the issue. It implies that the refractive index is different at different frequencies. Hence, light at one frequency has a different group velocity than light at another frequency. This has been known since Hertz. It was explained by Einstein.

Lene Hau's experiments at the Rowland Institute are a little more difficult to explain.

It is a little easier to explain something related to her experiments: Bose-Einstein condensates. Naively, you can think about light as billard balls. If you hit one ball moving at a given velocity in a given direction with an identical ball moving in exactly the opposite direction and same velocity, then by momentum transfer you can cancel the motion of both balls. When you do this with light you create a Bose-Einstein condensate.