No, I will say that you don't have to worry much about this point. Actually this type of problem may occur when the car gets in touch with water. But the corrosion on this nut bolt is just in its prelim stage which can easily be overpowered. You should apply some lubricant on this nut after removing this corrosion by rubbing it with a sand paper. Regular Lubrication to the auto-parts not only protect them from corrosion, but also enhance their life.