Yes, the airport protest absolutely got out of hand and was an egregious mistake. Some of the protestors are clearly losing the plot. From what I have been able to determine elsewhere online, they have collectively realized it and are discussing changes in tactics.
It was clearly a trap - but the protesters let their emotions take over their judgment (Which is exactly what protesters were accusing the police of doing in the first place). At least from what I'm reading online, the protesters are learning from that mistake.
Even blocking the entrance to the restricted area was a rash decision anyway - they want to shut down the airport like Monday, but simply doesn't have enough people to "congest" the departure area like Monday. Thus, they decided to block the entrance, and in turn, cross the line of tolerance that airport authority had been allowing - i.e. as long as you don't disturb the operation, the protesters can stay. Also, they lost their plot as they forgot the whole purpose of protesting at the airport - i.e. spread the message to an international audience. By blocking the entrance, they pissed off some of the people that sympathized with the protesters.
When the anti-extradition bill that started all of this was proposed, the initial march (the June 9 one with 1m people) was legally sanctioned. Protestors assembling around the HK Government complex afterward were attacked by the police and pepper sprayed. Demands to withdraw the bill were ignored, and the government took an overtly patronizing tone toward the protestors -- which was not well received in this city where some 80% of the population has a tertiary education. Subsequent events are well documented: the even larger (2m) march; the pattern of attacks by police on civilians, passersby, and the press; the ongoing concealment of police identities in these events; the storming of LegCo and the defacement of mainland Chinese emblems; the Yuen Long, Tsuen Wan, and North Point triad attacks; and so on. Yes, the airport protest absolutely got out of hand and was an egregious mistake. Some of the protestors are clearly losing the plot. From what I have been able to determine elsewhere online, they have collectively realized it and are discussing changes in tactics. This is not an issue of mob violence: it's a catastrophic failure of governance and policing.
You mistime the initial event a little bit:
June 9 - the initial large protest with 1M people. Only to see Carrie Lam respond with "The bill is still going ahead", thus, angered tons of HK people.
June 12 - The protest on the day which the bill was suppose to be read/"debated" in the legislature. The protesters assembled around the area where the legislature along with the gov't office, only to be tear gassed and pepper sprayed as the police moved in to "disperse" the crowd. There was also an incident where protesters had retreat into one of the office building (CITIC Tower) in the area, only to see the police pushing towards them, nearly causing a stampede. Further throwing fuel into fire, the police went into hospital to arrest some of the injured protesters.
June 15 - Carrie Lam announced "suspending" the bill. But it did not reduced the anger of HKers.
June 16 - The 2nd large protest with 2M (+1) people. IIRC they surrounded the gov't office area again afterward, although the crowd eventually dispersed peacefully.
The continuing police brutalities only fuel the protest more, culminating on July 21 during the Yuen Long incidents where a triad mob openly assault anyone in their path in the MTR Station with the police literally just either watching in the background, or walked away from. The police later assembled outside the walled villages where the white mobs are assembling, but didn't arrest anyone right there. That was when things got into the current "path of no return" anyway. Arresting a few of the white shirt mob after the fact was literally glossed over - especially when those white shirt mobs were charge with nothing more than "illegal assembly" even with multiple videos of them assaulting passerbys.
P.S. Tear Gas Buffet in Sham Shui Po again...