The eModule inside your helmet which houses the camera is very tough. Whenever it is turned off, or runs out of battery, it will automatically stop recording and save the video file. It would take a very extreme impact to prevent the helmet from correctly saving the video file.
At forcite we have put the helmet through extreme crash testing, and only a direct and extreme blow directly to the camera lens has been able to damage the camera PCB in a way that could prevent a saved file.