I’ve had two mavic platinum pros crash on me so far and thank God they were covered under warranty .You may think these things are very dependable they are not . Once again you may think that they’re dependable they are not . They’re not perfect ,if yours hasn’t come down and crashed it’ll come down and crash. I have had 2 spiraled out of control and come down and crash . In a Clear open area .
For whatever reason electrical / Circuit board problem or rotor problem etc. I don’t know there should be some sort of diagnostics thing to plug into it prior to flight takeoff like you do in a car that finds the errors . Hopefully before it becomes a crash .
On top of that they’re overpriced .
My two cents.
That kind of spiral event sounds suspiciously like the result of yaw errors arising from an incorrectly initialized IMU heading. If so, then it's not a hardware fault - it's more a result of the lack of instruction from DJI on how to avoid it.