Unfortunately (after several misleading emails) DJI assistance held me responsible for triggering the Palm Land during a flight that had just taken off via Palm Launch.
I am absolutely sure that I did not operate the palm land because immediately after takeoff I moved two steps from the drone and there was nothing or no one under the Spark.
But from the Spark data it would seem that something was less than 0.5 meters away ... and that's why the Palm Land descent started.
The flight was too short (between 3-4 seconds between take-off and landing) so as not to have the Flight Record of that flight.
Has this happened to anyone else?
Is it possible that DJI does not admit that the drone independently triggered the Palm Land due to a sensor evaluation error?
Now they don't give me back the drone I sent for assistance, they don't reimburse me, they don't replace it for me.
Nothing!

So you sent the drone in because it landed by itself?  You can disable gestures control I think.

This what i did (as many other times)
1) ignition of the Spark,
2) waiting for the GPS signal and connection with radio control,
3) palm launch
4) forced land and absolutely not generated by me
The flight time of the third flight was about two seconds or since the drone turned on the engines following the Palm Launch, forced takeoff and landing.

Hi, I do apologize for what happened and for the whole situation. I am afraid to tell you that the solution to your case remains the same. Please do understand that we consider your satisfaction and to provide the support as far as possible, however, we only based the decision on the data that we have and the information that you have provided. We hope you understand. Thank you.

You have drawn conclusions only from your data.  But I would like to ask you a question: how do you look at a sensor error if you only consider the values ​​that the sensor has made the drone believe?  
That way you will always have reasons!  
I know that the Spark didn't behave as it should have and now the drone is broken and completely lost ... but it's not my fault.  It is not a pilot error.  
But DJI makes the rules ...
I guess it's hard for Dji to admit that the sensor was wrong in detecting the diatanza from the ground, thus activating the Palm Land autonomously ...
Many thanks :-(