I don't know what happened that day but I can tell you about my experience getting directions from a cop. I was a passenger in a car driving slowly through the center of a small town. We were stopped at an intersection when a very irate cop started hollering directions. We did what he told us to do and he went berserk. Either he was having a left-right confusion or suffering from roid rage but he wrote the driver a big ticket. We all went to court for the driver and the case was dismissed.
I've. always had very positive interactions with police but some people have had some very bad experiences. This particular cop had his own company that provides 'expert' police witnesses in accident cases. I suspect he was excited about the prospect of supplying police experts when the family of the man who died was sued.