show me the person, I will show you the crime.
“There's no way to rule innocent men. The only power any government has is the power to crack down on criminals. Well, when there aren't enough criminals, one makes them. One declares so many things to be a crime that it becomes impossible for men to live without breaking laws.” ― Ayn Rand
That said, eating is as much a distraction as holding a phone and creates an equal danger, so I can't say the cops are wrong.