Rebellious dragon teen, listening to dragon metal bands, hanging out with like minded rebellious human, drive by disrespecting the councilman?
Adolescent dragons are not entirely herbivorous. As growing youngsters, they do need a bit of protein in their diet.
At this stage, they normally go out on their own. It's sort of a rite of passage. An adventurous ne'er-do-well, who manages to team up with such a youngster, can manage to "train his dragon" in ways the adult dragon society might not approve.
The councilman would do well to let them pass.