Yes and no. For any given breed, one color earlobe is considered correct and one is considered wrong. But sometimes a chicken will have the "wrong" ear color for their breed. So they definitely exist, but according to the breed standard they are not correct. For that study, when I go skim-read the text, they had quite a few with white earlobes, even though that is "wrong" for the breed. Earlobe color has no effect on egglaying ability, so it might get ignored in a commercial flock, which is probably what happened here.This link below shows RIR's can have white or red ears... https://www.researchgate.net/figure/Rhode-Island-Red-chicken-hens-with-the-white-or-red-earlobe-color-a-Red-earlobe-chicken_fig1_305926887#:~:text=., 2023).-,Among these, red earlobes and white earlobes are characteristic of,et al., 2023).