APM 2.5 autopsy (Sudden Loss of Control in alt hold)

APM 2.5 3DR
MK 2 GPS
3dr Power module
AC 3.1
Trunigy 9x with FrSky module
Frysky Delta-8 Receiver running PPM to APM
3dr telemetry (the new one with USB and 6 pin cable
HobbyWing 4in1 ESC
TBS discovery (Black Sheep quad frame)

This was the maiden flight on this airframe. AirDroid connected at the time. I don’t understand the log, would anyone be able to tell me what caused my horrific crash?

Destroyed during the crash:
2 motors
4in1 ESC
Airborne telemetry
APM 2.5 (has a burnt smoky smell) might still work
2 Booms
The frame

You need to provide a dataflash log from the APM