Auto Tune Crash after roll tuning, help me analyse logs please

S550 HexaCopter
Emax 2216 810kv
Emax 30A opto ESC
2x 4s 3300 in parrallel
8m gps module
APMCopter 3.3
Frsky X9D
Frsky X8R /Voltage Sensor(flvss)/Gps Telemetry module

Hey all,
I maidened my new hex last night and everything seemed fine after a 12min flight so I decided to try autotune today.

Took off in stabilize mode and switched to althold and engaged auto tune, the hexa seemed to do it’s thing tuning roll, but after about 6 mins in it violently pitched backwards about 60°+ in what looked like a fly away then crashed into a bush before I could switch out of autotune and take over
I’m new to APM and I’m not quite sure what to be looking for in the logs as to a cause for this.

Any help is appreciated.