Beach Episode: The turtles have their own version of this in the sewers. Justified since they can't go to an actual beach.
Chekhov's Gun: Lace-Face. The turtles use it to bring Raph back to sanity.
Companion Cube: Raph's tire and football, which he named "Lace-Face" are this to him. He even bluntly calls them his emotional crutches.
Covered in Mud: Leo, Donnie, and Mikey end up like this after falling in some sewer sludge. It causes Raph to mistake them for monsters.
Failed a Spot Check: Raph fails to notice his brothers arrive despite them being in plain sight.
Freak Out: Raph has a couple of these throughout the episode. It actually works in his favor when his panic drives him to beat up the Sando Brothers. It later devolves into straight-up Sanity Slippage.
Skewed Priorities: When Raph first gets separated from the group, Mikey cries out that they lost their football. He acknowledges Raph when Leo and Donnie glare at him.
Raph: Boys, we're good-doers. And what do good-doers do? They good-do. And they good-do it well.
Digging Yourself Deeper: The turtles' attempts to do good deeds only cause harm, making public opinion of them worsen even further.
Missed Him by That Much: One-sided example. Mikey manages to steer the turtle tank away from the crowd before they can turn around and see it, making Stockboy look like a liar.
Never My Fault: Leo claims that the disasters in the photos were all somebody else's fault. He's notably a bit unsure of that statement.
Only Sane Man: Leo votes to stay in the sewer while people are panicking about mutants. Subverted when he's immediately joins his brothers to try winning over the town anyway.
Right for the Wrong Reasons: The crowd assumes that Baxter's news about the mutant menace was just a publicity stunt. They're right, though Baxter actually did have mutants to reveal.
Weaksauce Weakness: For as advanced as Baxter's drones are, they apparently aren't waterproof.