You write very well.
The law aspect of this is interesting to me, bec. I am a lawyer (scary admission there). But lay persons don't always realize the hedge of rules and restrictions that has grown up in criminal trials. Sometimes it seems unfair and counterproductive . . . but the rules really are there to try to keep the innocent from being railroaded. Sometimes that means that the guilty get lucky (or have a better lawyer), but the alternative is something like the French system, which I feel is fundamentally unjust.
In the English system (which is ours as well, generally speaking) the courtroom is like a sports field or a boxing ring, with each side fighting as hard as it can for its case, with the judge there as a referee to see fair play and the jury to score the fight. This means that each side is digging with all its might to find all the evidence that may help its case. That tends in the long run to uncover the truth.
Obviously the system has flaws, because if one side has a much better "fighter" it tilts the odds one way or another. Usually, though, it's the prosecution that has the advantage, with all the machinery and unlimited funds of the State arrayed against the private citizen. So rules have grown up to make the prosecution dot each "i" and cross each "t", to counter the State's advantage. A very wealthy defendant can tip that balance back the other way.
In the French system (and other European systems) on the other hand, the theory is that the judge and BOTH lawyers, the prosecution and the defense, are on a quest for "truth" and all work together to "find the truth". You aren't really represented by your own lawyer in that system, because his first duty is to the truth. Problem is, sometimes everybody thinks they know what the truth is before they really get started, and the result is shoddy investigation and complacent acceptance of the obvious solution (as in the Dreyfus case). So you get more unjust guilty verdicts under that system, while in ours you probably get more unjust acquittals.
Given the choice of imperfect systems, I think ours is better.