In offline mode, attempts to spawn Relic Wraiths can only use your own record files: that raises the fail rate considerably. I didn't want to give the item back because I wasn't fond of the idea of people slamming the poor toaster server with "find me a Relic Wraith" requests in the case where they were online and there just happened to be no relevant ghosts.
But, spawning random monsters instead might be a nice compromise.
I'll put it on the feature list: the current build is pretty slammed, but it will show up sometime after that.