Some of my post alludes to previously reported aspects of the case which are not shown in the video. There were many eye witness accounts of what happened, and they are easy to find in a google search if you're interested. Some of your assumptions about what happened (based on your viewing of the video) are factually incorrect. Darcy was never run over by Bryant, and in the video he is only hit once by the car (the first two lurches forward didn't result in contact). In addition, Darcy's girlfriend had called the police on him earlier in the night due to drunken domestic violence, and eye witnesses describe Darcy as throwing garbage and pylons in the street, screaming at motorists, and doing figure 8s to block entire lanes of traffic just prior to his encounter with Bryant. Bryant claims he was threatened after his car first lurched forward, without hitting Darcy (Darcy presumably felt this was a purposefully aggressive, and responded in kind).

The whole point is that Bryant's car was stalled, meaning that he couldn't simply drive away if Darcy moved to the passenger side. This is why Bryant panicked. (Furthermore, when Darcy eventually did make it to the side he attempted to punch Bryant, grab the steering wheel, and hold onto the moving car).

I agree here that Bryant's mishandling of his automobile should have been prosecuted. I don't drive a manual transmission, so you could be right about his explanation sounding fishy. But I still think it makes more sense that he lurched forward thrice in an attempt to start his car, rather than he purposefully tried to ram Darcy and had the misfortune of stalling all three times.