Really bad batch.
"I’ve bought many times over the years and this time I was very disappointed with the oysters I got to show off with family on the 4th of July. Out of the 100 oysters I purchased, probably 40 to 50 of them completely broke during shucking, making it impossible to enjoy them. The shells were very brittle and it was a complete mess. I never saw anything about “delicate” shells on the web site, otherwise I would not buy them. Really dissatisfied this time, maybe it’s time to look into other providers and get my money’s worth."