the membrane is arond the cotys, not the 2nd set of leafs, so it's not that... did you drip soemthing on it? or is the soil really hot for seedlings? could have been damaged while sprouting.
If on a tight schedule, definitely start over.. when possible plant more than you need... then no time is lost if you get an inviable seed, mutation or self inflicted mistake. Doesn't matter how... some seeds just don't make it. Common practice in gardening hobby.