Emergency managers take note--should you have a future problem.
Some may think the answer to avoiding public failures of your warning system is to "not test the system," Which is the wrong tact to take.
See this story about a glitch in a San Francisco warning test, Delayed Emergency Alert Test does little to discourage those in San Francisco.
I believe that a major issue with warnings is that they are not practiced enough. They are not practiced because there is risk in doing tests that don't go according to plan. This worrisome approach to warnings only ensures that future "actual warnings" may be--to use a technical term, "messed-up."
The explanation given by SFOEM was a good one. Figure out what went wrong and -- fix it! Then test again.