What evidence do benjamin and sarah abbot offer as proof that martha carrier is a witch? in what ways is this evidence subjective?

Benjamin and Sarah Abbot accused Martha Carrier being a witch because Benjamin fell gravely ill after his argument with Martha over a land property. In Sarah's testimony, she also claimed that her husband's illness was not the only thing that Martha had caused. She said Benjamin's cattle strangely died without a natural reason. They used these reasons as proof that Martha was a witch. However, their evidence was subjective because they had no physical evidence to prove. Their accusation was merely from the fact that Benjamin fell ill after he argued with Martha.