Cop horse bumps another cop

The officer on his horse had just finished rushing up onto the sidewalk and engaging in a melee. I saw a number of clubs swinging. When I got closer I saw that he was pushing someone with his horse into an storefront's iron grating. It looked to me like things could be getting uglier until someone distracted him by throwing a plastic bottle. He then changed his focus and whirled his horse around, which is when the officer in the foreground was pushed. The mounted officer didn't seem to notice, but charged through the crowd, presumably looking for whoever threw the empty plastic bottle.

These photos were taken from the source video which was used to produce this video:

http://www.indybay.org/news/2003/02/1575268.php