That's how I fell about it. I think it's insane for anyone to believe that he is some sort of insane racist clod blooded killer, out for blood on that night and he followed him with every intention to commit a murder of a young black kid. Some people actually feel that way, I've talked to a few of them. It's crazy. He wouldn't have called 9/11 or whatever and stay on the phone with them for so long during most of the timeline if he wanted to do something that crazy.
I think he was legitimatly worried about his community, and when he saw someone unfamiliar in the neighborhood after having bad things happen in the past and nothing was ever done about it, he decided to follow someone until the police arrived so that they could be sure to catch who was believed at the time to be a suspicious, unfamiliar, individual. Plenty of people do that every single day and it usually doesn't end up with someone like TM being killed. I've tailed people before after calling the police myself, have it be someone walking through our area (although to be fair we lived way out in the country so there is never a reason for anyone to be around unless they were up to no good) and I've tailed obvious drunk drivers before also. Heck, I've been TOLD to follow certain drivers at times.
What he shouldn't have done was if he was going to follow him, he shouldn't have done it so closely so as to be spotted and then leading to any sort of confrontation. That was his first mistake, and that is on himself. I think what happened was a series of mistakes on both sides. I think TM was, rightfully, freaked out that he was being followed. If you were being followed you would likely call the person out if you realized you weren't going to get away. In doing so Zimmerman felt threatened, them TM felt threatened, and then whatever happened happened. Both guys were likely confused and assumed the worse, and one thing led to another and a horrible mistake was made. It never should have happened, in the end that much is clear.
I think either Zimmerman walks away entirely and then loses some sort of civil case, or he is found guilty of a lesser charge and does no more than a year or two behind bars. He certainly isn't going away for life or anything like that.