You have been cited under § 1.05 of the Public Courtesy Code: Unsignaled Reversal of Direction
OTHER PEOPLE EXIST.
You spun a hundred and eighty degrees, mid-block, without so much as a glance. You have never once been the only person on this street. Not once. Check behind you the way you'd check a mirror.
This is not a fine. There is no fine. Think about what you did.