What is the legal defintion of improper ping in the State of Maine?

I am trying to find the legal definition of an improper p in the state of Maine. I recently got a ticket for an "improper p," however when I began the p the line was broken, but had just become solid when I completed the p. I argued with the cop who could not clearly tell me why it was an inproper p. I plan to contest the ticket so I need to locate the legal defintion of an improper pass in the state of Maine. Any help would be appreciated!