I dont think that it is a disease, but don't quote me, but it happened to me, the blossom was opened too early, and it dried up, and if exposed to too much moisture, could mold.

Thanks! Interestingly, since I initially posted, the bulb has put out another flower stem which looks normal.

@salpal - I was worried about that. Thanks for the input.

Or it could be red blotch? Heres a link on how to solve it if it is.

Thanks, I'll keep it in mind if I see signs of it this year.