Tailless VTOL crash log

I took off like a Drone, and quickly switched to fixed wing mode. And it immediately started turning (without my input). And then leveled out for as second. But when I tried to turn away from the powerlines, it started flipping. So I disarmed it so that it would not hit the powerlines.
I am trying to understand what went wrong I could use any tips so that the next flight is more successful. I had a M8N GPS attached but it refused to get a fix, so I tried without it.
Attached is a slow motion video and the data log:

51 12-31-1979 18-00-00.zip (648.1 KB)