On my way home today I nearly lost my head...

You had a bout of roadrage. It's a normal reaction to the idiocy of others. What you hadn't considered was the end game. What was the purpose of you having words with him? At the time it seemed like a good idea and you wanted to call him on his shit. What you didn't consider was that he didn't want to hear you, and he was prepared and willing to take the next step. You obviously were not since you were in a position of disadvantage (still clipped in on the bike).

This was probably the best ending for this incident. Now, for future such incidents, I'm sure you'll have a plan. Just be aware that people in San Francisco have been killed by being struck in the head with skateboards. You need to prepare now and decide how far you want to take the next incident.

You need to know where your limits are and what you are willing to do in case you get in over your head. Again, people get stabbed, shot, and run over in San Francisco a LOT.... most times it never makes the news.

It'll happen again. You just need to determine if it's worth your life or worth taking the other person's life.  You obviously have some civility in you because your thinking shows that communication was your goal. What you failed to consider is that people are crazy and they don't give a crap about others. Life is cheap out there.

Vent more. Daydream about revenge and/or karma getting the guy. But in the end, live a happy life and fish more. That guy won't live another 5 years. His poor life choices will make sure of it.

I'm glad you weren't hurt... from the crash or by being brained.

Too bad no go pro footage! 

That's just how skaters from tenderloin say hello during pride weekend

What ever happened to public arrest? If you would have pinned him down, the cops certainly would have been called. When they arrived and you had him pinned down, could you have told them what your reasoning was? Is that even a thing any more (if it ever was)?

You mean citizen's arrest? Yeah that's still a thing. I citizen's-arrested a guy once. He attacked me at a bar un-provoked. He told the cops I was giving him "bad vibes."

I had no intention of doing that here. Just wanted to give him my two cents. My lesson is it's not worth it.

yeah, citizens arrest. Late night.

Thanks for all thoughts and input. Definitely a learning experience. Life is too good to risk injury over something that stupid and avoidable.
Going ab diving tomorrow...