The Hawaii emergency management worker, fired earlier this week after almost 12 years on the job, said he did not hear someone repeating the word "exercise" before the Jan. 14 drill because it wasn't played over a speaker, CNN reported.
Instead, he focused on the exercise's words, "this is not a drill," which came from a voice he didn't recognize.
"I did what I was trained to do," the worker told NBC News. Push notifications were sent to cell phones belonging to Hawaiian residents and alert messages were played on local television.
CNN and NBC News did not publish the man's name, citing security threats on his life.
Once he realized the exercise was a drill and not a real threat, the man said he "just wanted to crawl under a rock."
Scared citizens called his colleagues, he said. Emergency workers sent a clarifying push alert about 40 minutes after the initial alert, sent around 8 a.m. local time.
About two weeks later, the Federal Communications Commission said the worker who mistakenly sent the alert was not cooperating with an investigation looking into what went wrong. That probe determined he was confused by the exercise cautioning that it was "not a drill," as he said in the interviews with CNN and NBC News.
Hawaii emergency officials "counseled" the employee in question at least twice before for mistaking drills for real threats, according to an internal investigation.
The man questioned the validity of those reports from the state and FCC. His attorney, Michael Green, said employees were ill-equipped to handle the drill.
"No one was ready for this day," Green said. "They were not ready and they were not programmed to do what they were supposed to do when this happened."
HAWAII - THIS IS A FALSE ALARM. THERE IS NO INCOMING MISSILE. THE ALERT WAS SENT OUT INADVERENTLY. I HAVE SPOKEN TO HAWAII OFFICIALS AND CONFIRMED THERE IS NO THREAT. pic.twitter.com/hwRGct2aTa- Rep. Tulsi Gabbard (@TulsiPress) January 13, 2018