On the morning of Dec. 17, when other vendors say Ms. Hamdy tried to confiscate Mr. Bouazizi’s fruit, and then slapped him in the face for trying to yank back his apples, he became the hero — now the martyred hero — and she became the villain in a remarkable swirl of events in which Tunisians have risen up to topple a 23-year dictatorship and march on, demanding radical change in their government.