That’s not an accurate summary of the ruling. The ruling orders the EPA to re-evaluate the safety of fluoridation, but does so because the statutory evidentiary standard here is preponderance, not overwhelming evidence.

(It’s also not a ruling “against” the EPA. It’s entirely consistent with the statute, and the EPA will presumably act in accordance with it and produce yet another study demonstrating marginal-to-zero harm associated with fluoridation below 1.5mg/L.)