OP did you even attempt to slow down or did you just figure it was his responsibility to get out of your way. Maybe he stayed where he was so that you could make a decision and go around or maybe he figured he'd take his chances with a bike at 20 mph rather than 2 tons of steel at 50...

Also, why does everyone seem to see pedestrians as a nuisance? If someone wants to do the earth a favor and walk/skateboard (or even bike) somewhere, couldn't we give them a break and be thankful they are pouring more co2 into the air?