The seed germinated so it was viable.
I also don't see how Greybeard would be at fault for bad seeds from a breeder that came in breeder packs. If the seeds are bad that would more than likely be a breeder issue. Or they could be old seeds but since these breeders don't date their seeds with the exception of ACE there's no way of knowing how old they are. They could have been sitting around for years somewhere.
Regardless, since Greybeard isn't the breeder it doesn't make sense to just single them out as the culprit for what you claim are bad seeds. If the seeds are bad that would be on the breeder. But since the seed germinated and popped through that bone dry soil it's more than likely a grower issue.
Spray that seed so the shell can soften up and fall off.
I have no affiliation with Greybeard and have never used them.