This is exactly what I have concluded with also. IMO RTH is extremely reliable if used correctly.
An other aspect I don't understand in this case, is why the Mavic continued full speed forward while auto landing.
The manual states:
The aircraft will land automatically if the current battery level can only support the aircraft long enough
to descend from its current altitude. The user can still use the remote controller to alter the aircraft’s
orientation during the landing process.
IMO this would mean that you can spin/turn the Mavic around while auto landing, but not move forward/backward/sideways.
In this case, did sport mode override this? Or was it due to the Mavic going into auto landing while full forward was was applied?