Not defending the cop at all, but this rider was also a total moron and did in fact precipitate the incident. First the dumb azz, after riding the left lane marker for a block (splitting), jumps ahead and then rides the white line on the shoulder side of the lane. That in itself is not correct positioning in the lane, unless of course he enjoys having cars join him in his little piece of real estate. But the part that really makes no sense is hitting the brakes while the cars ahead of him are pulling away from him AND the cop is trying to merge into his lane behind him. Unless of course he was trying to precipitate the whole thing. With all the numb nuts running around these days looking to sue someone or just looking to get attention, I can't rule out anything. Anyhow, I wouldn't want to be riding near either one of these guys.
Jerry