Appeals courts do not make decisions on what the facts are, they only decide if there is enough evidence in the record to support a finding by a trial judge.
So if Expert A says the sky is blue, but Expert B says it's red, the judge believes Expert B is more convincing, rules that the sky is red because B presented hundreds of pictures of pretty sunsets, but A only presented a few showing the sky is blue because obviously that's the case during 95% of a day (more evidence was introduced that the sky is red) the CAFC can't overturn that finding of fact, which is clearly erroneous? (the sky can indeed appear to be red at sunset due to sun angle to the horizon and different wavelength scattering compared to during the daytime) That can't possibly be an actual outcome, defies logic.