Yeah, actually is does prove something. With a firm grasp of what recessive and incomplete-dominant mean we know that a recessive allele could not partially repress an incomplete-dominant allele at a given locus and so there would indeed be a visual phenotype if you were dealing with an allelic pair. And the fact that the Fire het Albino looks like nothing more than a Fire tells you that the WT allele at the Fire locus is partially repressing the Fire allele at said locus and theretofore, Albino and Fire cannot be allelic.
And Mike, I disagree with you slightly on the SuperFire Albino. SuperFire would not fully mask the Albino presence; the eyes would be red.