Okay, I'm gonna weigh in here. I've been working in the criminal justice system since 1994, at all different levels and different positions.
First, I have never heard of a prosecutor who says "case dismissed, but that doesn't mean the person isn't guilty." Does it happen? Yeah, when witnesses crap out on you, or evidence is lacking. But I've never seen that said out loud to the press...
Second, if a defendant is going to be offered some type of alternate resolution to criminal charges, the charges aren't dismissed until after the defendant completes the requirements of the alternate resolution. Why? So when the defendant fails to abide by the terms of the agreement, you don't have to start over from the beginning.
Third, I've never seen a prosecutor agree to seal a record the same day it's dismissed, and expunge it so quickly. Especially for some type of alternate resolution, and before the terms are fulfilled.
Fourth, I've seen juvenile cases get assigned more community service for a lot lesser charges. Hell, last case I was involved in, a 17 year old was given 40 hours for a misdemeanor criminal damaging case for egging a neighbor's shed.
I'm certain something stinks here. Wonder if we will ever find out the rest of the story...