I don't know about the evidence you're referring to. It's certainly possible that a material object can travel faster than light in a medium other than vacuum. One of the results when charged particles do this is called Cerenkov radiation. Phase velocity is faster than c and the group velocity is less than c, but phase velocity doesn't transmit information.

I don't think Tachyons should be called God.

Not admitting that experimental refutation of SR or GR exists (if it does exist tell us about it and perhaps we'll have the next Nobel prize winner) let me rephrase what I said: terms like Tachyons can be introduced to facilitate discussion about hypothetical objects even if they don't or can't exist.