I was performing a pre-programmed Litchi mission for the third time when suddenly, during the return to home phase the P4P suddenly started spinning uncontrollably, hit a tree and crashed to the ground. The rotors were smashed but the motors continued turning extremely fast. Couldn't kill the motors either by using the Litchi app or the controller sticks, so pulled the battery. P4P is now irreperable. How can I report this to Litchi and get some kind of compensation? I've attached the relevent Litchi flight record as a CSV file....

That CSV file is very hard to read as it's full of nonsense numbers for the (important) pitch, roll and yaw parameters.
But  why would you expect that Litchi should compensating you?
For that, you'd have to be able to show that it was a Litchi issue that caused the incident.
If the drone did as you described and spiralled to the ground, that indicates loss of either a propeller or motor.
But the chances that Litchi caused that are zero.
It would have been due to a faulty or improperly fitted prop, or a hardware fault in a motor or ESC.

I would agree, spin and crash sounds like one of the motors failed or a lost prop. Could be the ESC, could be the motor etc

Thanks - it appears I need to concur. I'd been reading recently of a number of incidents involving flyaways and uncontrollable drones when in Litchi Waypoint mode, so I assumed that would be the cause.

Geoff Goy Posted at 9-17 07:55
Thanks - it appears I need to concur. I'd been reading recently of a number of incidents involving flyaways and uncontrollable drones when in Litchi Waypoint mode, so I assumed that would be the cause.

Litchi is a well proven and reliable program.
I've never heard of or seen flight data that showed any problem incidents that were caused by Litchi.
Any incidents described as a "flyway" would almost certainly be due to operator errors and misunderstanding.

Hi, Geoff. Thank you for reaching out and we're deeply sorry to know about the incident that happened to your unit. In this kind of situation, I'm afraid that you may consider sending the unit in for a proper diagnosis. You can contact our support team to start up a ticket at https://www.dji.com/support. Thank you for your continued support.

Looks like a motor/props failure

Does anyone know how to kill the motors if they don't respond to either the control app (Litchi or DJI GO 4) or the manual controller, other than pulling the battery once the rotor blades have disintegrated?

Geoff Goy Posted at 9-19 02:38
Does anyone know how to kill the motors if they don't respond to either the control app (Litchi or DJI GO 4) or the manual controller, other than pulling the battery once the rotor blades have disintegrated?

Yes.  What you are describing is a Phantom that has landed upside down.  The motors will continue to spin.  You can carefully grab the landing gear, hold the drone right side up at arm's length, and use your other hand to shut off the motors with your controller.  

Tried that - didn't work. Nothing I did with the controller had any effect on the drone's motors, even when holding it the right way up. I had to hold the drone next to a wall so that the rotors smashed before being able to safely reach the battery and remove it.

Okay.  Did you do a CSC or left stick down?  

I tried both. Also switched flight mode from P to A and S and back. Nothing....

You sure you held it for 3 secs?  If it didn't work, then something is awry because it should work.  Good luck.  

Held it for several seconds - maybe 10 to make sure. I can only assume the electronics were damaged in the crash and there was no remote connection between the drone and the controller.