When the power went out in their hotel – a common occurrence in parts of Africa -- Roberts said the usually steely nerved Dicken became very nervous.
"He freaked out, picked up his phone ... runs into the other room talking to the CIA to have them reposition his satellite so he can make sure that the rebels aren't coming to get him," Roberts said. "He says, 'alpha, bravo, niner, niner, six, two, the fishing is good in Catalina.'"
Then, tipped off by a friend back home, Roberts and the team watched an expose about Dicken that had been posted online by retired SEAL Senior Chief Don Shipley, who runs a SEAL-style training camp in Virginia.
"If I get one more phone call asking me to verify if A.J. Dicken was ever a Navy SEAL, I'm going to take this grenade, pull the pin and blow myself up!" said Shipley in the video.
There are only about 2,500 active Navy SEALs, among the elite of the elite in the U.S. military. Shipley and his brothers in arms say it's a slap in the face for people to pretend to be SEALs. Shipley had made it his personal mission to ferret out phonies and uses a special government database to keep track.
"I verify, on average, at least 20 fraudulent SEAL claims every day," he said.
Shipley had been tracking Dicken's activities for months and said he knew immediately that Dicken was a liar. He said those discharge papers Dicken claimed to have were fakes printed off the Internet.
"All I gotta do is check your name," he said. "I can look at your picture in the newspaper and tell you were never a SEAL."
Shipley said Dicken was a different case from the others. For one thing, his claims, showing off medals and discharge papers were so over the top. He said he even blew up an earlier scheme where Dicken tried to con a filmmaker out of $50,000 by claiming he was the SEAL who killed Osama bin Laden.
"Oh, he says he has got two Medals of Honor, that hasn't happened since World War I ... a POW? There's no listing," Shipley said. "A.J. has a mental problem, and I go after the worst of the worst."
After the Burundi team saw Shipley's video, the last bit of Dicken's cover was blown and the expedition became a rescue mission.
"You're sitting in the middle of Africa with somebody that you're pretty convinced at this point is a sociopath at best, a psychopath at worst," Roberts said.
Back in Nevada, the two doctors, already on the hook for hundreds of thousands of dollars, wired thousands more in emergency cash to bail out Dicken and the rest of the team. After they made it home, Roberts wasted no time blowing the whistle on her boss.
"I went to one of the doctors with all of the evidence I had and said, 'You have a problem,'" she said. "It was all a great big fraud."
Dicken fled Nevada. Roberts said she believes she and others fell for his ruse because he "brought a level of plausibility."
"He wouldn't tell these outrageous stories just right off the bat," she said. "He would drop little bits of things that are plausible. And he would tailor that plausibility story to each person, knowing what they knew."
Dicken kept a low profile for months, but in February, KGO, ABC's affiliate in the San Fransico Bay area, tracked Dicken to his parents home in Southern California, where he denied ever having claimed to be a Navy SEAL -- and promptly disappeared once again.
This past fall, "20/20" tracked Dicken to a secluded property in rural Arkansas. When "20/20" finally caught up with him, he refused to comment.
Now Dicken faces felony firearms charges in Nevada, thanks to videos he had made at the training academy in Carson City that showed him firing a variety of high-powered weapons. Because Dicken is a convicted felon, he's banned from owning firearms.
Dicken's now-debunked claims of SEAL glory have the people who say he conned them hoping to see him wear a very different kind of uniform -- the orange jumpsuit kind prisoners wear.
"My payback is going to be my satisfaction," Roberts said. "I would like to see Dicken … arrested and brought to justice. ... He's a coward and a liar. That's all he has been, and that's all he ever will be."