The tomato throwing incident occurred in January and a protester was arrested and charged with assault. A
few days later Trump was warned that there was information that more tomatoes were going to be thrown from the audience. That's when Trump said, "if you see anybody throwing tomatoes, knock the crap out of them, I'll pay your legal bills".
I'll tell you, if I were at an event with my kids, and people started whipping objects at the crowd or speaker, I'd make sure my kids got to safety, and I'd try to stop it. At the very least, I'd thank the guy with the stones to knock the bully out.