However, the OP was giving a rough approximation in the first place, in saying that all natural distributions follow a Gaussian curve. But Gaussian curves go from -∞ to +∞. Many of the real-world distributions must only have positive values, like heights and weights. Although for real-world purposes, they can usually be approximated as Gaussian.

With that roughness in mind, I think it's okay to say that the Stefan–Boltzmann law, the inverse-square laws of Newtonian gravity and electrostatics, or Kleiber's law, which are all listed in the Wikipedia link are close to a power law to be acceptable counter-examples.

(Stefan–Boltzmann assumes a perfect black body, the inverse-square laws ignore relativity, and Kleiber's law is a rule-of-thumb in the first place.)