Waves shouldn’t have any significant influence, as all we see in the video are some small ripples and the light is mounted in fairly high above them. My money would be on, as you put it, “negative refraction”. The listed temperature for the first clip 21 degrees, presumably Fahrenheit. Water freezes at 32 degrees, so because the pond isn’t frozen, the water temperature must be greater than that of the air, and by a pretty significant amount, as corroborated by the strong inferior mirage seen at the opposing shoreline:
The red line in my insertion to mark the approximate location of where the inferior mirage starts. Later on
Originally posted by Metabunk.org