Defect PID after autotune in ROLL

Hi everyone,

I tried to autotune my drone in Roll and after the values was calculated, the drone start to oscillate from left to right.
This is the second time i try to autotune and and both time I crashed
I used the orange cube and i have an octocopter drone in X that is 2,8m diameter and 26kg weight.
To securised the flight put in place all the security as say in the documentation : http://ardupilot.org/copter/docs/autotune.html?highlight=autotune. Althold, and ch7/ch8. I also put the accro mod to try to stabilize the drone if the problem become bigger.

So as write in the doc, i land off with the althold mode, then i click on ch7 to autotune the drone. The drone start to autotune and did it well. When the autotune in finished, the drone was stable. i did a lit turn and stabilize it again. Then i click on ch7 to have the low position and then in high position to try the new PID. This is at this moment the dorne start to oscillate. I click one more time on ch7 to go back to low position but then the drone didn’t stabilise. After that I try the accro mode but it was to late. I crashed!!
Can someone help me to understand what’s the problem?

Follow this link to have all the dataflash logs from the flight controller

Thanks for your help!

Ivan