Attacked by a "local" while minding my own business - I keep surfing

It was an OK morning of surf in Playa Grande. There is a storm overhead so it's kinda mixed up. I was minding my own business (I still can't hear very well due to ear infection, and I was wearing ear plugs) and David attacked me, hitting me with his board and telling me to go surf somewhere else. I did not. After this he paddled away once I told him I knew his name. Do not let dudes like this intimidate you in Costa Rica. He is just a punk who thinks he owns the place. Like most of them he just threatens and then goes away. He doesn't even live at this beach. There are dudes like this all over the world and they are a dime a dozen. Just mind your business, don't cut anyone off, and keep surfing. Have any of you had any run-ins with David or guys like him? Tell me in the comments!! Pura Vidaaaa