Barr should have supported a lenient plea bargain for the public peace, raising the suspicion his real intention was for Chauvin to be found non guilty, as many conservative pundits appear to have predicted would happen in a trial.
It would have been a lot easier for a plea deal to have been attacked as the "system protecting their own."
You yourself are arguing he shouldn’t have been found guilty and simultaneously justifying Barr for believing a second degree admission would be too lenient, you gotta make up your mind.
This was early on, when, as I remember, at the time most conservatives said it looks like he's guilty (based on the video).
Also, Barr was worried that "it would be perceived as too lenient"