Well if it looks like a solid white mass oozing out, then it's probably not hatched. I've seen that happen before where the egg never really developed properly and goes through a kind of "abortion" process.
It could have been an unfertilized egg or the embryo died for some reason. Remember in the ocean, the mortality rate is high, which is the reason that animals have so many babies. If every female S. bandenis laid 200+ eggs and each one survived, the ocean would be teeming with cuttlefish (wouldn't that be fun ).
Not sure, but the ones I have seen looked like little mutants maybe partially mal-developed... some lumpy, some with eye spots and without. Looked at through a 20x jewelers loupe and most didn't even resemble a cuttlefish.