Those are good markers. I've never seen the black line veer off into the white belly space before like that, that's kinda wacky....

They're good markers, but no, they're not definitive. My proven het lavender albinos also have het pied markers. On the female the markers were so strong, I worried for years that I'd been sold the wrong kind of het. But she's never produced any pieds, just a visual lavender albino. And all of her babies ALSO have "het pied markers".... So who knows what those "markers" mean.