Hmmm, this thread looks ripe for a dissenting opinion!
But first a caveat: I do agree that this topic will not work if it comes across as whiny victimization.
However I don't think that it's inevitable for the topic to read that way. I think the topic will only make you seem like an "embittered crusader" if 1) you veer beyond the facts into unnecessary emotional elaboration and 2) you let it get boiled down to something pat and oversimplified.
What I saw in reading your summary though, was that you did learn more interesting and complex lessons beyond something trite like "justice is important" and "some lawyers suck".
Take this line:
---> "I learned through my case that how easily the truth could be distorted and manipulated. And how difficult and complicated to establish one little truth."
That shows that the experience taught you something that will carry over beyond your own ordeal to how you approach the practice of law. It can also be used to show that, even though you saw your own case as being black and white, you realize that when you're on the other side of the fence, as a lawyer or adjudicator, interpretation can be a very tricky game (whether played with sincere motives or not).
And another good point:
---> "Only reason I did not lose faith in my case was because at least I had great faith in my lawyers. Not only they were skilled to be a great lawyer but also their attitudes toward morals and justice were something I could fully respect."
Hey, look! role models who you've depended on in real-life and not just romantically idealized from a Grisham novel. That could be interesting, also seems to have taught you that attitude (including perserverance) is as important as skill.
Basically: I think there is potential for this to be thoughtful and fresh, so long as you stave off the temptation to let it degenerate into cliche. And I think you can't tell how these things really come across or if it'll sink into the quicksand of whiny mundanity until you've actually tried writing [certainly each revision I've tried on mine has brought up new points, and made me re-think my approach].
...I'm not saying this is a sure-fire winner, I'm just saying don't throw it away until you've at least given it a shot.