The question says that he jumped from a 4-story building, it does not say that he jumped from the 4th floor, that is, he jumped from a window on the ground floor, which is low and no harm was done.
The question says that he jumped from a 4-story building, it does not say that he jumped from the 4th floor, that is, he jumped from a window on the ground floor, which is low and no harm was done.