I found this very interesting

[OhhWatALoser]

I heard the theory...it just doesn't make sense to me. I LOVE genetics. I would marry genetics if I could (yes, I'm a nerd). If he only had one copy of the mojave gene...he wouldn't express it as a bell. It would still be like a mojave gene and a damaged wildtype gene. I guess logically his theory doesn't make sense to me. Something that makes more sense (if only to me), is that the mother either A. was a very bad example of a mojave (it would be nice to know what HER parents were) that was just assumed to be normal or B. there is some other gene linked to the mojave gene. One gene that controls the actual pattern and one unknown gene that's paired to it. Then the mother could have a damaged mojave pattern gene, but when the other gene is paired with the mojave, it then expresses the super form.

excuse my comment, i misunderstood.

mojave is an incomplete dominant to wild type.

When two wild types are paired together, it looks normal.
When a mojave and wild type are paired together, they are both expressed as mojave.
When two mojave genes are paired together nothing is expressed but the mojave gene (BEL)

the theory is, when the mojave and wild type scenario comes up, the wild type gene is damaged in some sort of way where it is not expressed. So all that is expressed is the single mojave gene, which we know is a BEL.
the wild type gene isn't there to make it look like a mojave. you don't need 2x mojave gene to make it look BEL, just need there to not be a wild type gene. which normally the only way to do that is to fill it with another mojave gene.

in short you need the mojave gene and the wild type gene to make it look mojave, without the wild type, it's going to just express the mojave gene, which is BEL.