It’s a little bit tricky to tell the full story here given the short footage, but we can assure you, it is a funny one.
Cyclist ‘A’ is seen at the start of the video cycling along when a second cyclist (cyclist B) pops up and passes them. Cyclist A, looking to win the place back, over steps the boundaries of the narrow bicycle lane and moves on to the main road where a Mazda MX-5 was about to come by. The driver honks, naturally, and is responded to in kind with a flip of a middle finger, and some obscene language (that's in the video, so do take this as NSFW).
As fate would have it, the karma police were in town, and acted swiftly and without hesitation, nailing cyclist A in the face with a lamp post, knocking them off their bike. Game. Set. Match.
Here’s remembering another instance the karma police we quick to take action:
Man Throws Brick At Mercedes-Benz, Receives Instant Karma To The Face