I've left comments everywhere on this thread because food safety deserves a lot of visibility. Summary here:
While this may not be standard terminology, these egg safety guidelines from the NSW government distinguish between broken and cracked eggs. (It also says that both are unsafe.)
- A broken egg has neither shell nor membrane intact
- A cracked egg has membrane intact, but shell not intact
Cracked eggs shouldn't be eaten says the FDA, the USDA, the NSW Food Authority, and the Departments of Health for Queensland and Victoria.
As is common of regulatory documents, links to original, peer reviewed research do not exist in the documents I just shared, so I am willing to believe that cracked eggs still could be safe, but I will not believe it until appropriate citations are provided.
My own speculation: sure, shells are porous, but they're still protection. One of the documents I linked instructed not to wash eggs with water, because the shell is more porous when wet and more readily allows bacteria through. Surely if the membrane were perfect protection, then a more porous shell would not matter.