I thought I was witnessing a "fly-away" that folks swear happens from time to time (tho I I believe most of them are caused by user-error). At 20% battery it was time to land, I flew away from the current home point back to where my backpack was and landed. I don't usually do a cnc (or whatever the wee maneuver with the two sticks is called) to shut off the motors, I just hold down the throttle till it stops. However, to my amazement before it shut off, just in that 3 secs where the motor is powering down, the fecking thing took off again on its own! I couldn't control it, no input from the sticks worked. It flew higher and slightly away from me and I thought it was just gonna head off into the sunset. I even tried grabbing the landing gear to prevent it from going off but missed (thankfully). I was stunned. What the hell was happening!? Then I looked down at the screen and it said "coming home". I had hit the 15% threshold where it goes home and lands just at the moment the rotors were powering down! Because I was away from the home point it tried to make it back there and took off. I just regained control, landed and turned it off quick as I could. I was a bit relieved I must say, that outcome is far better than a "flyaway" anytime! Phew.