Crash in the exchange of flight modes

 Hello everyone, it follows description of the aircraft that I have:

Pixhawk 2.1 (cube);
Firmware 3.6.9 if chibios
Futaba t6j sbus reciver;
Rdf 900 if castle bec 2.0
Digital spektrum servos;
Engine t engine;
Esc castle phoenix edge 50 (he gives power to the servos);
Lion 8s 7ah batteries;
Airframe rvjet;
Sony a6000 camera (powered if castle bec 2.0);
Emlid for ppk.

Can not say the reason for the fall, I already fly with this plane several times, about 5000 ha, 10 hours, I took the mission before it finished, because it was a test flight only, after that I told him to enter the mission again and the same answered as expected, then I activated the rtl, I expected the same back home, and when I went to put the same in fbwa, and it spiraled.I noticed the flight logs that the same entered in manual mode, and I spiral, I would like help to define if it was my mistake at the time of changing the key, there was some mechanical failure (example, voltage drop of the servos bec), some Firmware error, because I am not experienced in analyzing the logs.
Lucky that the damage was not many, only one wing and the wing servant I think I will twist by security
logs and imagens in the link:!AgTCVcTndvUrlhVD-ePg2pC9rjnM
Thanks to all who can help.

A quick look at the log shows me human error.
You can see a switch to Manual at the beginning of the decent and a switch to RTL after it is too late.