Good luck in your fantasy attempt to make this a parallel situation. In this particular situation a law enforcement officer (in fact the elected sheriff) called 911 and stated that at man threatened to kill him (which was a lie), This was a very different than the Zimmerman situation which involved a civilian calling 911 & where no lies were stated in his 911 call, nor did he engage Trayvon in a verbal confrontation (until Trayvon violently attacked him).
It should also be make clear that the police urge us to call 911 if we are worried about suspicious people in our neighborhood. In fact the police re-enforce this every year here when they come out to present at our neighborhood watch meeting. You should ALWAYS without exception call 911 when you are concerned for your safety or concerned about suspicious people.
As another note -- there is no law against you walking or driving in your neighborhood following someone. You are allowed to walk or drive wherever you want in your neighborhood. Is it wise for you to attempt to follow a suspicious person? No. But I will note that many of our crimes locally are solved because a civilian stepped up and followed a suspicious car (or people) -- this includes a recent bank robbery and recent shooting within the last month in our Raleigh/Durham area.