Most of this flight was normal:but at 7:28 and 7:35 in the video you will see extreme tilting of the horizon along the roll axis accompanied by a strange oscillation. I located both tilting incidents in the log, at 545 seconds and 553 seconds. Although the log shows a brief rc_aileron input at this point, the MPP was hovering without rc input. In fact, when I saw the strange oscillation on my screen, I attempted to bring the bird back home but it would not respond to inputs until the oscillation stopped. Once I regained control, I immediately flew back home, but I would like to try to understand what happened before I resume flying. Has anyone else experienced behavior like this?