What version of Data ONTAP are you running on the system?
Starting with DOT 8.1, AutoSupport content is context-sensitive. The rc.txt file is not always included with every AutoSupport.
Also, size and time budgets were introduced. There was a known issue with the leak-data file being too large, causing the collection of the rc file to be skipped. It was fixed in 8.1.3 and later releases.
If it sounds like you might be in this situation, you can verify what was supposed to be collected and its collection status by examining the manifest.xml file that is also included with the AutoSupport message.