http://www.photographybay.com/2014/01/14/dji-responds-to-phantom-flyaway-concerns-and-safeguards-in-phantom-2/

Known as a 'FlyAway', erratic autonomous flight has been reported in drones using a Naza flight controller from DJI, most notably the DJI Phantom. During a FlyAway pilots see the drone FlyAway, ignoring their control input. In a few cases, normal control has been regained. With symptoms inconsistent between reported instances, the cause is difficult to pinpoint. Manufacturer DJI has been reluctant to acknowledge the problem.

User Reports
A survey of FlyAways was started by PhantomPilots.com user 'Spork'. Phantom and Naza users are encouraged to fill out the survey regardless of if they have experienced a FlyAway or not. The survey is available here and survey results are available here.

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With 39% of survey responses confirming at least one FlyAway with their Naza flight controller, an official response from DJI seems reasonable to expect. The only good news received from the survey comes from Naza-H owners with no reported FlyAways.

DJI's Response
Eric Reagan, a journalist for PhotographyBay.com, posted his FlyAway inquiry from a DJI Q&A session during CES 2014. The recorded response is posted here on YouTube.

Unfortunately for Phantom owners, DJI's response to the FlyAway problem was to blame users for not properly following the instructions.

Analysis of a FlyAway
Seeing an expensive piece of equipment disregard your commands and take off in a random direction is frustration at an unparalleled level. Because so many of these FlyAways drones are lost never to be seen again, video footage from any FlyAway can be incredibly valuable in diagnosing the problem. Additional On-Screen-Display video overlay information coming from the flight controller, like what the DJI iOSD offers, can be valuable in conveying internal information about the flight controller at the time of the FlyAway.

After reviewing several videos of FlyAways posted on YouTube there seem to be two different types of FlyAways.

Toilet Bowl
The first is where the drone enters an erratic flight pattern similar to the way in which water drains down a toilet, see here and here. This could be caused by incorrect IMU information causing the drone to become unstable and unable to self level.

Return-to-Home
The second is when the flight controller receives faulty GPS information either on takeoff when the home location is recorded or in-flight causing the drone to think it is too far from its original takeoff point. In either situation the drone flies in a straight line towards its destination, see here and here.

Our Best Guess
With inconclusive evidence as to the cause of FlyAways we can only make a best guess as to what causes this erratic behavior with some Naza flight controllers.

GPS Glitches - if the flight controller is not programmed to throw out garbage GPS information (an updated location is suddenly more than a mile away), the drone may think it needs to 'return home' causing it to fly away from the user. This doesn't take into account user override input like switching the flight controller out of GPS mode.
Component Failure - drones are complex systems and electronic manufacturing is difficult; solder joints may crack leading to bad connectivity and components may fail without warning. Check out the 'Bathtub Curve' entry on Wikipedia regarding manufacturing failures.
Unexpected Failsafe Activation - failsafe settings can be changed through DJI's software. Loss of signal and low battery are the two most common failsafe settings. However, neither is likely to cause a FlyAway unless concurrent with a GPS glitch causing the drone to think it is far away from home.
Electromagnetic Interference (EMI) - components like the speed controllers and motors can create significant EMI which may interfere with the compass (magnetometer) and possibly the GPS radio. For this reason the magnetometer is positioned on the landing gear, as far from these EMI creating components as possible.

You are joking, aren't you?
The DJI Responds article you referred to was from January 2014.
The Phantompilots thread you referred to was from 2013 !!
DJI drones have undergone a massive evolution since those days.
Back then, very few flyers properly understood how the drone works and how to fly it.
There was a lot of myth and misunderstanding and reported "flyaways" were common.
Any incident where the drone was lost and the flyer didn't understand why was called a flyaway.

Ever since the release of the Phantom 3 in April 2015, DJI drones record the data from a flight.
The flight data can be analysed to find the cause of flight incidents.
And the overwhelming cause has been operator mistakes and confusion.
Drones don't just fly away, there is always a cause for lost drone incidents.
There are occasional genuine hardware or software issues that might cause a flight incident.
But analysing flight data shows that these are very rare.

Flight data analysis has also led to improved understanding of how drone flight works and dispelled many myths that are evident in your post.

Your analysis and best guesses are incorrect or irrelevant for a number of reasons.
They suggest a number of things that just can't and don't happen.

None of this is relevant to the Phantom 4 pro.

Hi Jonni, I am sorry for the accident that happened to your drone, I understand your frustration. As per checking, the data analysis of your case is that the record ended without any sign of abnormality, so we could not verify what happened afterward. It did not indicate a pilot error or the drone's issue. However, since your drone is beyond the warranty period, therefore, a free replacement can not be issued. We can provide a solution to you based on our policy. Your case is still following by our team, please wait for the update. Thank you for your patience.
And for your information, when an accident happened, we will need to check the data that we can obtain and try to find out the cause case by case, guessing or assuming the cause is not accurate. Thank you for your understanding.

DJI Susan Posted at 11-1 18:53
Hi Jonni, I am sorry for the accident that happened to your drone, I understand your frustration. As per checking, the data analysis of your case is that the record ended without any sign of abnormality, so we could not verify what happened afterward. It did not indicate a pilot error or the drone's issue. However, since your drone is beyond the warranty period, therefore, a free replacement can not be issued. We can provide a solution to you based on our policy. Your case is still following by our team, please wait for the update. Thank you for your patience.
And for your information, when an accident happened, we will need to check the data that we can obtain and try to find out the cause case by case, guessing or assuming the cause is not accurate. Thank you for your understanding.

I am very disappointed in DJI so far. This is not a positive customer experience that I will share with my peers. I sure hope you find a resolution that meets us both half way so I can share a positive customer outcome in the future.

Jonni Armani

Jonni Armani Posted at 11-2 09:15
I am very disappointed in DJI so far. This is not a positive customer experience that I will share with my peers. I sure hope you find a resolution that meets us both half way so I can share a positive customer outcome in the future.

Jonni Armani

But you aren't interested enough to have an independent analysis of your flight data?

Labroides Posted at 11-2 14:04
But you aren't interested enough to have an independent analysis of your flight data?

Its already been sent to DJI (the entire flight folder) and they said "it wasn't my fault and it wasn't the drone's fault" so somewhere there is a "mysterious entity" that is responsible for this.... #this is what Liberalism looks like-

Total unaccountability- this is how companies go out of business- total FAIL- This is why I pay a legal counsel-

J.

Labroides Posted at 11-1 18:45
You are joking, aren't you?
The DJI Responds article you referred to was from January 2014.
The Phantompilots thread you referred to was from 2013 !!

If I wanted your opinion I would have asked for it-

Jonni Armani Posted at 11-2 09:15
I am very disappointed in DJI so far. This is not a positive customer experience that I will share with my peers. I sure hope you find a resolution that meets us both half way so I can share a positive customer outcome in the future.

Jonni Armani

I understand your request, we will escalate your request to the managerial department for further assistance. They will contact you soon. Thank you for your patience.

Thank you, Susan.)

J.