The driver of a vehicle in front of the one you are driving has the right direction indicator on his vehicle on and, at the same time, with his arm in a horizontal position and the palm of his hand extended downwards, warns him that he is going to pan left . Which signal prevails ? .
The luminous one, because the ones made with the arm are in defect of the optics .
That of the arm, because it cancels any optical indication that contradicts it .
Neither, both are worthless and precautions should be taken .