Shell said: Being inexperienced at the whole "seed thing", I left them on the plant too long and bowievels seem to have had their way 
These are Hibiscus Beetles (althaus hibiscus) The adults feed on the pollen but they lay there eggs in the fruit while the flowers is still open. The larva borrow into the forming seed and chew their way out when they are adults. So you didn't wait to long to harvest, it was already to late when the flower opened. You have to prevent the adults from ever laying their eggs. I put organza bags over the flowers when the buds are starting to form and remove them when the pod are ready to harvest.
http://garden.org/ideas/view/H...
You could probably remove the bag after the flower has dropped and the calyx has closed around the fruit but I leave them to make sure.
