Who is Tiddy from Among the Enemy and what is their importance?

Tiddy is an officer with the Population Police. He is the only officer who manages to escape the gunfight, and he does so with Matthias's help. On the way back to base, Tiddy promises Matthias that he will be accepted as a Population Police officer-in-training, and he goes directly to the commander and shares the story of how Matthias stepped in and saved him. Tiddy is described as self-confident and well liked.