Kevin says words to the effect that spider to spider is not lethal and then moves on. That can be taken two ways:
1. There are living homozygous spider ball pythons.
2. Mating a spider ball python to another spider produces living young.
If Kevin meant #2, then I agree with him. Even if homozygous (super) spider ball pythons die before hatching, mating two spiders would still produce living spider and normal babies.