Why can a accepted hypothesis be rejected at a later date

Toorale man murder mystery < - your lab link 1. how was the toorale man found? 2. what did archaeologists learn about the burial? why is the burial important? 3. what information were the scientists able to learn from the skeleton itself? 4. why is the question of whether the injuries came from a stone or steel weapon important? how could scientists distinguish between the different types of weapons? 5. what did the carbon dating and soil testing tell scientists about toorale man? why are the dates interesting for scientists?