The freelance writer was among a group of around 40 people waiting for the last Tube one night at London's Notting Hill Gate when he noticed a tourist drunkenly showing off on the platform.
But laughter soon turned to panic when the man suddenly leapt onto the tracks below and lay down.
Within seconds, the tunnel behind him filled with light from the headlamps of an oncoming train, leaving James with a split-second decision.
"People on the platform were laughing at this guy's dancing", says James, 31, from Vauxhall, West London.
"But the mood changed instantly when he climbed down and lay across the track. He then started shaking his body as though he was being electrocuted.
"People were screaming at him to get back up but it was all for show and he didn't appear to realise a train was heading right at him."
As onlookers stood frozen in horror, James leapt onto the track and dragged the man onto the platform, with no thought of the third live rail.
Seconds after James pulled himself up, the train roared past and ground to a halt 20 metres along the track.
"I was still kneeling on the platform edge as the train came past," recalls James. "It sounds like a cliché, but I didn't really think about the danger. It was gut instinct. I guess it was just a part of me."
By the time James was back on his feet, police officers had arrived and arrested the man, who was later fined for his actions before being released.
Tube train driver Trevor Bellinger later told British Transport Police how he only saw two figures emerge from the darkness ahead at the last minute.
He said he was so sure he would mow them down that he could only slam on the train's brakes and close his eyes.
BTP says the man would almost certainly have died had James not put his life on the line to drag him to safety.
Sergeant Jon Redman adds: "If Mr Pout had not acted in the manner he did we would have been dealing with a very badly injured or dead person on the tracks."
James says: "Afterwards people wanted to shake my hand. One girl even came over in tears.
"But I never felt like a hero. I was more annoyed about having got my new yellow jeans dirty. I was just plunged into this very weird, once-in-a-lifetime situation.
"People do heroic things all the time," he continues. "This was magnified because there were lots of witnesses - and it's not like I threw myself onto a hand grenade."