
Quoting
aardvarc
The officer who witnessed the infraction can ask another officer to write the infraction in any number of different situations, including the relatively common case of being offduty and not having his ticketbook on him. The statement of the first officer that he witnessed the infraction gives another officer probable cause to write a ticket or make an arrest or whatever. For example, if officer A sees a bankrobber fleeing a bank, and the bank robber jumps on the subway to escape, Officer B can be waiting for him at the other end of the subway and make the arrest, even though Officer B never saw any of the events. He only needs the statement from Officer A and it'll be up to Officer A to articulate the reason or what he witnessed. Your case isn't as dramatic, but the same principle applies. So you'll get officer A on the stand and make him make his case for the citation.