I did that, too with the first batch I planted..of which two of six are up.. Those seed cases are hard as a rock. It took the first one forever for the leaves to work the brown seed case off. I thought it was a clump of hardened dirt. On the second one, I pried it off..probably not good to do, but it's still alive, and the leaves are greening up. I know they say not to keep the soil wet, but I have it on the soggy side of moist right now.
Hey ..... just talking to my SIL and “whining” about my cucuzzas not germinating. I related your experience with them & how hard the brown coverings are, etc. She has a horticulture degree and a major green thumb and told me that for seeds that are hard to germinate, take nail clippers and nick the edge of the seed to help the leaves break through. I am definitely going to try that as soon as my two ‘new’ cucuzza seeds come off their long soak.
I need to talk to her more often! :-)