Between the check-in aisles of Hong Kong International Airport last night, a maelstrom of masked young men in black swirled around the limp, pinioned figure of an accused enemy mole. Many in the crowd pushed their way to the centre to strike him or bellow obscenities that seemed to make the vast terminal building shudder. Paramedics tried to move him to safety but were stopped by the crush of angry protestors.

It was a scene that made many in the city wonder: how did we get here? This was the movement made world famous by its almost absurd levels of civility: from uniformed students doing their homework on occupied streets to armoured frontliners collecting recycling and tidying the streets where they had just locked horns with riot police.

Now, these polite protestors looked more like a lynch mob. The standoff lasted over four hours until police arrived and protesters met them for a bloody clash at the airport entrance.

So how did we get here? The answer to that question lay mainly in the previous weekend, when police escalated their suppression of the protestors’ unauthorised marches by deploying tear gas in the closed environment of a metro station, shooting protesters with “less lethal” ammo at point-blank range, dressing as their comrades to ambush retreating activists, and, most shockingly, shooting a young medic in the eye with a beanbag round and blinding her for life.

These actions heightened the protestors’ anger at police, while the undercover operation bred a dangerous level of paranoia just waiting to bubble to the surface.

"Eye for an eye" - Protesters highlight police violence in Hong Kong Show all 13 1 /13 "Eye for an eye" - Protesters highlight police violence in Hong Kong "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester blindfolds herself during the occupation of Hong Kong airport following an incident where riot police allegedly shot a teargas canister into a woman's eye Reuters "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester with her right eye covered lies down in the arrival hall during the occupation of Hong Kong airport Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester holds up an alternative design of the Hong Kong metro system map that marks the locations where police have used teargas against demonstrators AFP/Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong Scores of protesters occupy the arrival hall of Hong Kong airport following an incident where riot police allegedly shot a teargas canister into a woman's eye Reuters "Eye for an eye" - Protesters highlight police violence in Hong Kong A breathing mask is seen on the ground where a protester received medical attention after she was allegedly shot in the eye by riot police Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong Protesters occupy the arrival hall of the Hong Kong airport Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong Blindfolded protesters occupy the arrival hall of Hong Kong airport Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester holds a sign that refers to an incident where riot police allegedly shot a teargas canister into a woman's eye Reuters "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester covers her right eye during the occupation of Hong Kong airport AFP/Getty "Eye for an eye" - Protesters highlight police violence in Hong Kong Protesters occupy the arrival hall in Hong Kong airport Reuters "Eye for an eye" - Protesters highlight police violence in Hong Kong As protesters occupy Hong Kong airport, a demonstrator covers his right eye in reference to an incident where riot police allegedly shot a teargas canister into a woman's eye EPA "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester covers her right eye during the occupation of Hong Kong airport EPA "Eye for an eye" - Protesters highlight police violence in Hong Kong A protester holds up a sign referring to an incident where riot police allegedly shot a teargas canister into a woman's eye AP

By the time protestors decamped and headed home, after exacting mob justice on another suspected agent provocateur, it felt like a sky full of dark clouds had smothered the movement’s light. As if on cue, an intense thunderstorm peeled over Hong Kong.

Unlike the 2014 Umbrella Revolution that rocketed figures like Joshua Wong to fame, the new anti-extradition bill movement is distinctly leaderless. Tactics are discussed in online forums and refined through trial and error. Decisions on when and where to march are made on the spot or through groups on the encrypted messaging app Telegram.

The goal is, the words of Bruce Lee, to “Be Water”: constantly changing shape, direction and form, and streaming through the fingers of those who try to crush it.

Yet in spite of the movement’s inherently diffuse nature, activists responded rapidly to the fallout from Monday night. In Telegram groups tens of thousands strong, statements were drafted and voted upon. Before the sun had risen they had voted to apologise for what had happened in the airport to the detained men and to the travellers stranded there. They then voted to call off a repeat of the airport shutdown and soon had a statement prepared.

“We must admit last night’s actions at HKIA were far too impulsive,” it read. “We have resolved to bravely face up to our own shortcomings. We sincerely apologise to the citizens who have always supported us.”

A draft code of conduct was even produced for future demonstrations, calling on all participants to cooperate with paramedics, to collect evidence on suspected moles and report them to the media rather than resorting to violence, and not to stand in the way of journalists’ work.

After just one night of collective soul-searching enabled by digital democracy, these young activists – many only in their teens – had shown a level of self-awareness and responsibility that has thus far eluded Hong Kong Chief Executive Carrie Lam. None of these countermeasures could erase the harrowing scenes of the night before, but as long as protestors showed they were willing to listen and self-correct, they can stay one step ahead of the government.

The battle cry of the anti-extradition bill movement – “Liberate Hong Kong! The revolution of our time!” – was coined by local philosophy student Edward Leung, former leader of the group Hong Kong Indigenous and current prisoner, serving a six-year sentence for inciting a riot. In a letter to activists last month, however, Leung offered a much milder message: “do not be dominated by hate,” he implored them, “in the midst of a crisis you must remain vigilant and continue to think and reflect.”