Maybe it totally does.
Would've been nice to hear that argued in a trial.
It would show the pointlessness of a trial.
Do you consider every trial where the accused is found not guilty to be "pointless"? The reason why we have trials is to present conflicting evidence and testimony before a grand jury to decide guilt. The physical evidence presented appears to support Darren Wilson's account, but it is by no means a "not guilty" verdict.
Given the grand jury decision, there isn't much question that Wilson would have been found not guilty during a course of a regular trial where the standard for conviction is much higher (beyond a reasonable doubt.)
A trial where the accused is very likely to be found Not Guilty is pointless.
A trial should only occur when the prosecutor is confident about guilt. I've heard some arguments that people wanted a trial to get to the truth, but that doesn't always happen. When there are ambiguities, it favors the defense.