Guns and women got Dan Bilzerian where he is today - the so-called “King of Instagram,” with nearly 23 million followers, a mansion full of guns and a hot tub full of women.

He lines his feed with photos of himself and women in the wilderness, playing with his arsenal of rifles, his biceps the size of their thighs.

Bilzerian once trained to be a Navy SEAL, and while he never became one, he often brags of his apparently deadly prowess.

“My greatest fear is that someone will break in and I won't be able to decide what gun to shoot them with,” he once wrote, beneath a photo of his table of guns. There's even an official Dan Bilzerian video game about shooting zombie women in the Nevada desert, and then in a city, with scoped headshots and bodies in the streets.

But on Sunday night, in the real Las Vegas, the Instagram star found himself caught in the worst mass shooting in modern US history. He saw a woman lying dead, he said.

He turned a camera on himself as he walked, short of breath, from the killing grounds, and at first resolved to live up to years of online bravado.

“Trying to go grab a gun,” he says in the clip. “I'm f— headed back... Saw a girl get shot in the face right next to me, her f— brains hanging out.”

But in the next clip, which briefly appeared on Bilzerian's Instagram account and has since been plastered over the internet, he stands in front of police lights, looking slightly dazed.

“Um, they got one of the guys,” he says, no gun in sight, all fury gone from his voice. “I'm headed back. I don't think there's much I can do.”

So he went home, leaving fans to wonder if one of Instagram's most formidable stars was something different in real life.

Bilzerian, who could not be reached for comment, would later claim to have helped an injured woman that night, when at least 59 people were killed and hundreds wounded.

And some did see something admirable in his return to the scene, armed or otherwise, even if it was by then too late then to help.

But for others, his flight from danger only proved what they always suspected.

“This is why children shouldn't classify heroes by their followers or their photos,” wrote Dakota Meyer, a Marine veteran who received the Medal of Honour. “Always playing 'operator dress up' and so so tough when the cameras are on. A woman just got shot in the head and you are running away filming ...

“Please stop trying to be someone your (sic) not.”

Whether Bilzerian really is the man he portrays himself to be has been debated ever since he first went viral, four years before the shooting, also in Las Vegas.

He was a small face in the background at the 2013 World Series of Poker - with a woman by his shoulder, stroking his thick beard.

For whatever reason, the clip spread.

As it did, details of Bilzerian's bizarre lifestyle fueled the sensation around him, and his growing fame in turn fuelled his eccentricities.

As GQ wrote in a profile, he was a “nosebleed stakes” gambler himself, having once lost $2.3 million on a coin flip. He grew up in an 11-bedroom mansion, and by his mid-30s had filled his Los Angeles residence with firearms (including a 20 mm antitank gun) and half-naked women.

Both were featured prominently in some of his most popular social-media posts.

“A kind of Bruce Wayne-meets-Hugh Hefner for the social-media age,” GQ called him.

Bilzerian doesn't sound like he feels the need to defend himself.

He told People he was on the Route 91 Harvest festival stage, hanging out with a singer, when shots began to rain down from the rifle-filled 32nd-story hotel room across the street.

“I was pretty calm, all things considered, but I definitely ran to safety,” Bilzerian told People.

He really did see a woman shot in the head, he told the magazine, and took another injured woman to a hospital before returning to the scene - as promised - with his gun.

But the police had things in hand by then, Bilzerian said, so he went home.

“I don't think it was heroic at all,” he told People of his actions. “I just wanted to do the right thing.”