Description of problem:
When the transfer rsync passes, it has the quiet little rc=0 to indicate this. When it fails, it has the equally quiet little rc=5, rc=12, or whatever the error code happens to be. 

If you know what you are looking for, you can sort it out, but it'd be helpful to have a more obvious error message letting us know when something broke. Something simple like RSYNC FAILED WITH ERROR CODE 5 or something could be enough, or maybe a little more information if it's possible without cluttering up the logs (as in, we don't want -v set by default on the rsync).