It was an internet café, so of course Kalinda went and got the browser history and saw that Mario was reading up on the police partner, who shot an unarmed Latino youth at some point and got away with it. So it seems Mario ducked over that day at lunch, Googled one of the main witnesses in the first-degree murder case on which he was a juror, and then came back full of ire, in time to flip the whole jury.
Alicia: "Cool! This is the thing we were looking for!"
Diane & Coyne: "No. The judge is getting really weird, we have to do this super basic."
Kalinda: "I'll go get affidavits from the other jurors that he brought in outside information."
Alicia: "I will help."
Kalinda: "Hell yeah!"
Even The Music: Gets cute.
Capstone: "Hey, we changed our minds about Grace and Zach for unspecified, shifty reasons. I may be being watched by someone or something in the corner of my office. Officially I don't want to set a precedent for parents using their influence and station to get their kids into private school: A thing that has never happened before."
Alicia: "Hey, Peter? Could you call that lady again? Apparently we're part of a hundred-year assault on the middle class that Reagan shifted into overdrive. If we don't get our privileged white kids into that school, we won't retain our hegemony."
Peter: "This is essentially my whole job now. It's always weird, the episodes that I am in versus the episodes that I'm not in. Cook County is on the case. The Case Of The Private School Waiting List!"
Kalinda: "Button Lady, this is my best friend in the... I mean, my associate. Alicia I'm So Sorry Please Forgive Me I Love You Florrick."
Button Lady: "I'm just crazy 'bout buttons! And your outfits in court."
Alicia: "Thanks! I'm wearing adorable slacks right now. Hey, did you happen to socially network with that entire jury so you could bother them about buttons all the time?"
Button Lady: "I sure did! Have you heard of that website Facebranch?"
Alicia: "No, and it's absurd. Not to mention the fact that Owen actually mentioned Facebook earlier in this episode by name. Any case, I'm glad I don't have friends if they're like you. For such a button lunatic you sure do have a fantastic house, though."
Button Lady: "It's where I keep my buttons!"
Alicia: "...Wait, and you're Facebranch friends with the judge, too?"
Button Lady: "Yeah, he friended me back immediately."
Alicia: "During the trial? Or -- as of one second ago -- the mistrial?"