They didn't word that very well.
Would have been clearer if they said "However, in other mediums (like water), particles can potentially move faster than light does in that same medium."
Ah, so it's not faster than c, it's faster than light's speed inside the medium. This makes a lot more sense.
Ah, so it's not faster than c, it's faster than light's speed inside the medium. This makes a lot more sense.