Principal yelled at me instead of backing me up.

I had a student this morning who told me that a certain troublemaker was throwing goldfish crackers at them. I checked the back of the bus and there was a giant mess. On the afternoon run I pulled up to the front of the bus line and shut it down. I stood up and addressed the issue and told the students "until I get a confession, we aren't moving" and...crickets. I called for a principal. They came out and yelled at me inside my bus and in front of my students that I should have just done the writeup that morning instead of waiting and then just gave a general "talking to" to the students and then told me to get moving. I'm pissed. This is why drivers quit. No backup from admin. Should I just let it go or how should I proceed?