On Fedora, the rpm command doesn't have a --rollback option.
But yum has a rollback command. But it doesn't take a date argument.
But if the rpm command is correct, are you sure it didn't complete? It gave a warning, not an error.
But if it didn't complete, you could try rpm's --nosignature switch to tell it to not verify the package signature. (But naturally, that's not advisable.)