As you probably know, Espionage is using OS X disk images to protect data (encrypted sparse bundle).
The logic behind these disk images are entirely Apple's, we are just using standard OS X commands to create a disk image of specific type, size and with specific password, the rest is done by OS X. When you unlock a folder, we send a request to OS X to mount this disk image with the password we provide.
When you add or remove files to/from protected folder, we are telling OS X to copy, delete files from the mounted volume, OS X does it for us.
The error you see is coming from OS X because it cannot do what we request. But all the operations are going through OS X so if something goes wrong, it is just the command which we gave, but was not executed properly, either because of a bug in OS X or because of an unexpected event, like for example disk corruption, power outage or such.
So, after a long preparation, the short answer is "no", we cannot do anything about it. You can try to run disk utility repair on it, this is what you did already. So the only other thing would be to restore from backup.
Soft RAID is nice, but it will propagate the data in a dumb way, like any other RAID, if the original is corrupted, it will propagate the corruption too (if it is a Mirrored RAID), so no help here.
Backup is an annoyance, util you need it....:-((((
Rgds
Zsolt