The event as such with a massive flight instability may very well be explained by a failing IMU. When this fails the data needed for a stable flight no longer can be gathered.
But agreed, it's strange that it is recovering ... hopefully we can see the causes once the right DAT is provided.
With the data already provided though... I can't see any problem approaching DJI with this.
Below in short for those eager to learn:
"For a drone to fly perfectly, the IMU, gyro stabilization and flight controller technology is essential. Gyro stabilization technology is one of the most important components, allowing the drone to fly super smooth even in strong winds and gusts. The gyroscope needs to work almost instantly to the forces moving against the drone (gravity, wind etc) to keep it stabilized. In the vast majority of drones, the gyroscope is encompassed or integrated within the IMU.
An IMU unit works by detecting the current rate of acceleration using one or more accelerometers. The IMU detects changes in rotational attributes like pitch, roll and yaw using one or more gyroscopes. Some IMU on drones include a magnetometer, mostly to assist calibration against orientation drift.
On board processors then continually calculate the drones current position. First, it integrates the sensed acceleration, together with an estimate of gravity, to calculate the current velocity. Then it integrates the velocity to calculate the current position.
To fly in any direction, the flight controller gathers the IMU data on present positioning, then sends new data to the motor electronic speed controllers (ESC). These electronic speed controllers signal to the motors the level of thrust and speed required for the drone to fly or hover."
