"Julia" tries to prove that she's Jo by listing off a bunch of facts about Jo, all of which are a matter of public record, so, way to not know any intimate details about yourself there, Jo. "Jo" remains calm and simply turns off the speaker so "Julia" can't say anything else. She can still hear Allison, who says they're going to keep "Julia" in GD jail until they do a psych work-up and redact her ass out of town, essentially ruining the real Jo's life. With that, Allison and Henry just leave. What's up with them being perfectly content to stick people who clearly don't deserve it in jail for long periods of time this week? First Larry, and now what is obviously Jo in Julia's body! They are both useless. "Jo" stays behind to tell "Julia" how sorry she is for taking over her life like this, which rings hollow when you consider the fact that she's still doing it and has no intention of stopping any time soon. Also, she swapped Jo's body for hers even though she knew that the body-swapping process made DNA destabilize, so that's pretty much attempted murder. I don't think you can really apologize for attempted murder. Not to mention the fact that she stole Larry's chance to participate in karaoke night. Unforgivable.
Carter sits on his platform and yells that he can't push the button and that this test is impossible. He wonders if that's the answer -- there is no solution. He takes the panic button out of his pocket, ready to give up, and that's when he realizes that its size and weight will make it the perfect projectile to throw at the red button. And it only took him 40 hours to do it! Carter really is dumb, huh? And yet, even he would have figured out that the Julia in GD jail is actually Jo. Anyway, the panic button hits the red button, and Carter pumps his fists in triumph and prematurely declares his dominance over the test. At this point, the lights turn off and we can assume that all hell breaks loose on poor Carter.