Other possible positions for GZ's car, plotted against a 4fps walking rate.
GZ at first made a mark on the map given to him by investigator Singleton (the female member of the team, and the first to question him on the night of the killing) nearer to the BLUE rectangle, but quickly equivocated his statement to move the car to the RED position.
It seems he may have intentionally left out a U turn or two and a middle observation point. The implication of this middle position is that he FOLLOWED the teen down TTL and this was the cause of the teen's running off the roadway and into the dog walk path. GZ is heard exiting his car seconds after telling dispatch "shit, he's running."
GZ seem to leave out the running in all his various versions he gave investigators.
This speculative path and timeline makes sense against the recorded call. That which GZ says happened, in various contradictory versions does not.