it's generally known to sow seeds at least 1/2" deep so that the seedling can jettison the seed pod.if the seedling emerges with the pod over the cotyledons it's a good idea to let it throw off the pod on it's own, as fiddling with tweezers etc can & usually will, damage the seedling/tear one or more cotyledons off, or halve the cotyledon.
i usually leave it until there's no choice but to interfere, whereupon the seedling's prob bu**ered anyway & i'll need to sow more.