No, the "scientific consensus" isn't clear that Piney Point did not cause red tide. Elsa was a likely contributing factor. Research into the extent of how the discharge from the former fertilizer plant is affecting the water is ongoing.

What algae is responsible for red tide?

At least three species of dinoflagellates and one diatom species are responsible for the toxic mess of red tides in the United States. These microscopic forms of algae produce toxins that can sicken humans and be fatal for marine animals.

What plant causes red tide?

Red tides are caused by algae, which are tiny, microscopic organisms that grow in the water. Almost all bodies of water have some algae, but in a red tide, there is a lot more algae in the water than usual.