One sentence, multiple problems with even basic facts.
Zimmermann is 28, not 26.
Zimmermann doesn't have a "well-documented history of bias against young black men." In fact, he actually helped to organise an activist group to get the son of a Sanford police officer prosecuted after the boy beat up a homeless black man and it was swept under the rug by the cops.
He didn't "take it upon himself" to patrol his community - that was his role as a neighbourhood watch coordinator. One which he was fulfilling because said gated community had experienced several break-ins in the previous few weeks.
Martin was not "significantly smaller" than Martin. Martin was 6'2", 160 lbs (and that weight is just an estimate which is probably on the low side), while Zimmermann is 5'9", 200 lbs (and, judging from his pictures, it isn't the "really muscular and in shape" type of short but heavy, either).
Zimmermann DID back off after instructed by the dispatcher. However, by that time, he was being pursued by Trayvon Martin, who apparently had the intention of provoking a confrontation, so retreating did not guarantee a lack of contact.
Attempting to get them to look at the facts is an exercise in futility.
Actually, a friend of Zimmerman says he weighs around 170, which seems reasonable from the pictures I’ve seen.
Martin: 6’3”, 160 lbs.
Zimmerman: 5’8”, 170 lbs.