You may have been terminated because you did a good job. I was terminated at a private school and the headmaster fired me. When all but one of my male students left the school the board investigated and he was terminated. I could not get the blackball lifted. My brother taught for three years in a New York high school. All his students passed the New York tests. He was terminated. No reason was given by the new principal because none was required. One of my old students was at a local school and had tenure. She was upset with the rules and told the principal she was going to quit. He said he would give her the lowest quartile in four grades—5–8 if she would stay. Her “bad students” started beating the “good students.” Her friends shunned her and after two years he asked her to leave. I got a job when the football coach was fired so they fired his wife.
You may have pissed off a student with an influential parent, a teacher who doesn’t like your style, a coach who thought you graded too hard, someone has a cousin, or… I have more examples but you get the idea.
Academics are not necessarily nice or rational people.