I think the opening pretty much told you everything you need to know. Scott is a big failure as an Alpha, a friend, a boyfriend and a human being. He's the Fant4stic Four of Alpha Leaders, but it's okay. Theo is there for him. He is such a great listener.
I honestly don't understand why there's so much animosity towards Theo. He's suffered so much. He watched his sister die. He had to watch Stiles butcher that poor, defenseless chimera. You heard his confession to Scott about how horrifying that scene was. Scott is an Alpha. He could easily tell if Theo was lying. But it's clear he wasn't. Scott believed Theo, therefore Theo told the truth. He revealed the harsh brutality lurking in the heart of Stiles, and showed Scott who his true friend is.
Even though Stiles is a psycho killer, Theo, was still willing to cover for him. He simply couldn't stand to break Sheriff Stillinski's heart, so he took the heat. He channeled his own perceived guilt for things into a tearful admission. Sheriff Stillinski did what I think we all wanted to do that moment. Embrace Theo.
I think this episode only went to show just how amazing, caring and wonderful Theo is. He's truly the Alpha leader we, the Teen Wolf viewers, deserve to lead this show into the future. I look forward to Theo replacing the total failure that is Scott McCall. It's going to be a wonderful future.
As long as Parrish gets out of jail. Seriously. I don't even really know what he did wrong. Sure. He occasionally blacks out, carries dead teenagers around, attacks his fellow deputies and tosses Jeeps around, but who hasn't made a mistake or two? He doesn't deserve to be locked away. If anything, he should be sentenced to community service. Preferably washing cars while shirtless. Yes. I think that would do nicely.
On a completely unrelated note...