His parents said the mental trauma their son endured from serving overseas -- coupled with the stigma attached to mental illness -- played a major role in his death.
NBC 7 obtained a copy of the medical examiner's report, which showed that his blood alcohol content was .34 percent.
In 2006, shortly before serving a tour in Iraq, Robert's mother Robin Andersen said he was struck hard by the suicide of his best friend and fellow Navy SEAL. By the time he returned from San Diego a year later, something had changed, she told the Post.
"I could just tell immediately he was changed," she said in the interview. "His affect was different, you know. The look on his face was a distance away."
Robin said her son was deeply bothered by the horrors of war.
"I was rubbing his back, saying, 'it's going to be okay,' and he said, 'Mom, it's never going to be okay.'"
Robert's father Bob Guzzo was also a SEAL. He said his son didn't immediately seek treatment for Post Traumatic Stress Disorder because he was told by others in the military that it could end his career.
"They told him specifically not to report on any worksheet that you are having these issues because if they do, they'll take your bird. They'll take your trident," Bob told the Post.
According to the Washington Post, Navy officials say that's not true.
Adding that the military actively campaigns to de-stigmatize the perception that reporting PTSD would harm anyone's career.
The stigma is you're weak,'" Dr. Michael Mantell told NBC 7 in an interview about PTSD. "There's a fear of overreacting and people saying 'we're going to hospitalize this guy, he's crazy' and there are judgments about this person's character, too. [People may think] he's ripping off the system."
After four months at home, Robert's mother encouraged him to see a psychiatrist in San Diego.
It seemed to be helping, but Robert was also drinking heavily and talking with friends about what he witnessed.
Last Veterans Day, he shot himself, leaving behind a family who loved him and a daughter who will never really know him.
"I'm not going to hide how he died," Robin said. "People need to know this is what happened and it could happen to other veterans."
Robin also told the Washington Post that other SEALs began privately seeing civilian psychiatrists along with her son because they too were afraid it would hurt their careers if they told the Navy.