A 24-year-old man accidentally shot by an FBI agent doing a backflip on the dance floor of a Colorado nightclub says he initially couldn't believe he had been wounded while enjoying a night out with friends and thought "some idiot set off a firecracker."

In an exclusive interview with ABC News' "Good Morning America" set to be broadcast Thursday, Thomas Reddington said he remains "confused" by the bizarre incident that happened at the Mile High Spirits Tasting Room near downtown Denver around 12:45 a.m. Saturday.

PHOTO: Tom Reddington is interviewed at his home in Denver, June 6, 2018. He was accidentally shot by the back-flipping FBI agent. (GMA) More

"We sat down at one of those picnic tables -- I heard a loud bang and I thought some idiot set off a firecracker," Reddington told GMA. "Then I looked down at my leg and see some brown residue ... I'm still thinking it's a firework ... all of a sudden from the knee down my leg became completely red. And that's when it clicked in my head, 'Oh, I've been shot.'"

Cell-phone video of the incident that has since gone viral on social media shows the FBI agent, identified by sources as 29-year-old Chase Bishop, dancing on a dance floor in the crowded bar when he suddenly did a backflip. Bishop fell forward, his gun slipped out of his waistband and landed on the dance floor.

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When he went to pick up the weapon, it went off. A bullet hit Reddington in his outer left leg just below the knee and exited his inner leg, he said.

"I like stand up and like start walking in a little circle saying, 'Hey, I think I've been shot. Can someone call 911?'" Reddington said.

He said he blacked out and either fell to the ground or sat on the ground. He said a good Samaritan used a belt to put a tourniquet on his bleeding leg.

"I blacked back in on the ground. Blacked back out. And then I woke up to a paramedic putting a tourniquet on my leg."

He said he lost a lot of blood.

"I soaked through several blankets, several towels, a few gauze pads," Reddington said.

The Denver Police Department is investigating the incident. Charges against the agent are pending the results of a blood-alcohol test.

An off-duty FBI agent reaches to pick up his dropped firearm while dancing. It accidentally fired and struck a fellow patron. (KMGH) More

Sources familiar with the incident told ABC News that the agent is based in Washington, D.C.

The agent "will be held accountable," one FBI official told ABC News.

But Reddington, who moved to Denver in January from the Chicago area, was reluctant to slam Bishop but said he would like a private conversation with him to clear the air.

"I don't want to blame anybody, throw anybody under the truck," said Reddington, who has retained a lawyer to represent him.

He said he's still in a lot of pain.

"It's bizarre. It's beyond bizarre," he said of how he was shot. "It's beyond comprehension I think right now for me just with all the factors involved.

"It's gone from being confused as to what happened. Being confused to what's going to happen. Being confused as to what's happening to me, where I am," he said. "There's been phases, but almost all of them have mainly just been shock, just various types of shock."

PHOTO: An FBI agent did a back-flip and his gun fell out at Mile High Spirits bar near downtown Denver, June 4, 2018. (Google) More

The owners of the Mile High Spirits Tasting Room say they're just as stunned.

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