So he tried to swat the fly and ended up swatting someone else.
This reminds me of a time in elementary school. It was recess and I was playing basketball with someone. He had the ball, and I tried to swat the ball away from him and I ended up accidentally hitting his body instead. He got mad and asked what I thought I was doing. I didn't say anything, just ran off the court and got as far away from him as I could while still being on school grounds. I was very glad when that recess period was over and we went back inside.