I wouldn't say code reviews are adversarial; they're collaborative. All members of a review are working to come to consensus on the best code that can be committed. When I'm doing them, if I see a better way to do an algorithm I'll go ahead and write the suggested code directly (GitHub has some great UI for this, incidentally).

An adversarial code review process would look more like attempting to solve a problem by having two separate teams devise a solution, and a neutral third-party chooses exactly one of those solutions to accept and discards the other. Team A, in this system, is not particularly interested in helping Team B succeed (and, indeed, within the rules of the process, has no incentive to improve the odds that Team B's solution is accepted).

This would be a hellishly-inefficient process (though, funny enough, something similar at the scope of project initiatives has been used at a few more Machiavellian corporate institutions). But it might be the sort of thing one could adopt if one thought, for some reason, that you couldn't trust that all development teams to collaborate cleanly (because their goals weren't aligned).

The notion that innocence or guilt (on a per-charge basis) as a binary state is very deeply built into our criminal legal framework. For any given charge, either the prosecution's case wins, or the defense's case wins. The prosecution isn't incentivized at all to help the defense win. And the judge's incentives optimize for neutrality... Because, the thinking goes, if they aren't neutral, their likeliest bias is in favor of the prosecution as a fellow agent of the State, which gives even more power to the already-powerful State authority, since the whole system assumes two things: (a) the defendant is innocent until proven otherwise, and (b) the State is a good-faith actor until proven otherwise. Generally, faith in (b) is almost never shaken without definitive proof (such as direct evidence of prosecutorial misconduct). Whether this means the prosecution is "dickish" as they pursue their goal of a conviction is a bit in the eye of the beholder, but note that nowhere in this process is the prosecutor obligated to assume the defense is a good-faith actor (and, indeed, if defendants were always good-faith actors, trials would be unnecessary and criminals would just confess their transgressions). And it is entirely possible that this system does not work without prosecutors leaning on defendants (in legal ways) under the assumption (on the part of the prosecutor, not the Court) that the defendant is guilty and hiding it.

This isn't the only model possible, but changing it would basically require restructuring the American criminal legal system from the bedrock up. Not impossible, but I wouldn't bet on it in my lifetime. What is heartbreaking in this case is that the pressure caused Mr. Swartz to take his own life, and without a prior diagnosis of likelihood of suicide / prior involuntary commitment, I have a hard time seeing any way for the legal system to account for that risk and still function. :(

... and of course, all this analysis ignores the elphant in the room that the Supreme Court dumped in the graveyard this week: we probably shouldn't have even thought of putting "used a computer in a way other than the way its owner intended its use" under the aegis of criminal law in the first place! That was a terrible use of the CFAA. But until this week, it wasn't understood that it was not a use of the CFAA.