I wasn't tailgating btw. There was no bike lane on this street, so I was on the free way on ramp lane, to the left as possible. The car was on the lane nearest to the freeway on ramp lane. He switched lanes without signaling, but had to stop in the middle because two bikers rode to his right to pass him. I was just behind him when it happened. I don't think I ran in to him come to think about it, I think I tried to swerve out of the way and I lost control.
I guess I had a number of options, but all the ones I could think of involved me on the ground.