The first start of the accident seems to have been

To put things in order..

1.
The first start of the accident seems to have been Bird Strike. This is not a 100% controllable variable for humans, so it can only be said that they were unlucky.
However, if a banger engine gets upset by eating a few flying animals instead of air, it usually just spreads and stops.
It only makes downhill and emergency landings because it can't ascend or fly anymore, and this is not a job for a civilian pilot, an expert with a transportation license.

By the way, all the hydraulic pressure for control goes out with only bird strikes, and the landing gear and the flap are all stiff, so it can't be unfolded manually? This seems to be an unusual phenomenon.

2.
The airport runway was too short, especially at the end of the runway, there is a lot of talk about "What a hard concrete hill?"
It seems to be true that the accident plane collided with this concrete hill, causing more damage.
However, since the structure was not legally problematic, it would be difficult to hold someone legally responsible.

In the first place, the plane didn't land at the terminal point so that it could use even the short runway, and it landed really urgently in the form of 'reverse driving' rather than the intended direction of progress. (What if it was an emergency!) Don't tell me that Bangi would collide with the hillside... There were a lot of bad news, but it actually happened.

However, if you're going to blame the bluntness, then when the plane continues to slide without obstacles and breaks through the airport wall at that speed and hits the outside road or private house!! It should also be considered comprehensively whether there were any other risk factors.
Only after the accident, "If we had started on the sea, there wouldn't have been a fire, would there have been a fire?" and "If it weren't for that..." You can blame it with your arms and teach it like this, because anyone can do it.

Well, as a result of this accident, all structures that are at risk of colliding with runaway planes on airport runways across the country may be removed or improved into a brittle form.
Just as all subway station walls are converted into non-combustible materials or seismic design is applied to buildings belatedly.

For your information, following the crash of Asiana Airlines Flight 733 in 1993, Muan Airport was created with the intention of creating an airport in the Honam area that is safer to take off and land in less weather than Mokpo Airport at the time! It is not for military use, but for private use, and it is an airport that does not have a coupe (limited take-off and landing during late-night hours). It is a pity that a bigger accident like this will occur.

3.
Next, the airline side.
Unfortunately, Jeju Air doesn't seem to have a very good reputation from travelers or even internal employees regarding the maintenance of its aircraft;
Even the next day after that accident, another airline-like type of Bangi returned due to a landing gear problem, that's obvious..

However, this is a symptom of psychosis. Due to this practice, the plane had become glassy due to poor maintenance, and during that accident, the landing gear failed to open. When it hit a blunt object, it exploded as if waiting and burst into flames..

Will it be possible to accurately prove the causal relationship? I think it's very difficult.
In the worst case, despite months to years of accident investigation, it may be concluded as 'unknown' in vain.

It's a frustrating and unfortunate accident,
I hope the odd conspiracy theorist or political sick person will shut up with this.

Long before the accident, the plane had been flying noisy and abnormal for such a long time that it could not help but attract attention from locals around the airport, so the video was taken too naturally.