Cyborg needed two rings to transform (this is proven when he drops his disguise when the first ring is destroyed, when he finishes beating up the robot). Later on, in Titans Tower, though, he still has his disguise, but only with one ring on.
The Titans were trapped in the forcefield two times already. "Only Human" was the first time, and notice that in both times, Cyborg was not trapped in either of them, which is probably the reason he was able to stick his hand in it in the episode "Car Trouble." It might have something to do with his technology...
When the Titans (with the robotic Cyborg) are ambushed by the HIVE students and Brother Blood, the robot Cyborg turns around to see them. How is that possible if Beast Boy didn't use the remote control to make it move?
When "Stone" and the HIVE kids are in the training room, Jinx only uses her hex blade spell. What happened to her sinkhole spell, telekinesis, and martial arts abilities from "Final Exam," and the fights earlier in the episode?
If Cyborg didn't go, who would have used the Ion Gauntlet? Remember, Brother Blood doesn't like Gizmo, and no one else uses advanced mechanical weapons like that, so...
As part of his initiation, Stone must carry Jinx's books. At the end of the scene, Jinx is suddenly carrying a book, as well.
Gizmo: (to Stone) What's your name? Oh, lemme guess. Snot Man? Is it Captain Nose Picker?
Jinx: Quiet. The headmaster is watching.
Mammoth: (Trying to lift a pile of gold bars) I could use a hand here.
Cyborg: How about a foot? (Cyborg kicks Mammoth in the face)
Cyborg: (To Robin via intercom) I've been really busy. I've been learning their combat techniques, weapons, armor, and we had a dance...
Robin: A DANCE? Cyborg, you're there to find out what the H.I.V.E. is planning, not learn to tango!
Cyborg: (Punches table) My name is Stone. And it looks like you have to find a new table.
Beast Boy: Do I hear an undercover mission coming on, 'cause I'm a master of disguise! (Turns into multiple animals)
Raven: Yeah, a green mongoose is gonna blend right in.
Robin: Sorry, Beast Boy. I was thinking of someone with a little better disguise.
Beast Boy: What are you going to do? Dress Cyborg up as a washing machine?
(Hits a fake cyborg, it falls over, Beast Boy screams, turns into a lizard, and sticks to the ceiling)
Cyborg: That isn't me. It's my fully robotic replacement. Not nearly as charming, but he can benchpress a bus.
Fake Cyborg: Boo-ya!
(Punches Stone in the face)
Stone: Boo-ya this! (Runs after fake Cyborg)
Robin: We're your friends.
Cyborg: Sorry, but I have new friends... PSYCHE!!!
Starfire: For your thoughts, I will pay 6 Grubfars.
Beast Boy: Oh, Cyyyyyyboooorg!
(All hold up a pink dress)
Robin: You left the Titans...
Raven: That means you have to be initiated all over again.
Fake Cyborg: BOO-YA!!! (Head pops up)
Raven: Something doesn't seem right here.
Beast Boy: Tell me about it, I can't figure out how to make this thing burp. (Robin, Raven, & Starfire make angry faces) What? I'm just trying to make him more realistic!
Stone: Mmm-mmm! Sloppy joes! Just like the mad scientist who created me used to make!
Jinx: (Sullen) You could have been one of us...
Cyborg: I could have been a lot of things.
Beast Boy: How do you get this thing to fight? Oh...
(Selects attack mode on fake Cyborg controller)
Fake Cyborg: Teen Titans, go! (Runs into wall)
Jinx: Don't bother trying to run.
Mammoth: You won't get far. The whole school is in on it.
Stone: In on what?
Gizmo: Whaddaya think, pie-for-brains? (Produces a dress and unicycle) Your initiation!
Stone: (Amused) Ha ha! That's it?
Mammoth: Don't laugh. You gotta EAT the unicycle.
Brother Blood was actually over 600 years old in the comics.
Jinx starts to show signs of not wanting to be a criminal when she says that Cyborg could've been one of them and he basically said it wasn't worth it. This will later come to a conclusion in "Lightspeed."
Although Brother Blood is apparently capable of transforming metal into flesh, this is the only episode that we see him do this.
Villain Debut(s): Brother Blood -- Although there are a lot of HIVE Acadamy members, none of them are introduced into later episodes, which foreshadows Billy Numerous, Private HIVE, See-More, Kid Wykkyd, Instigator, Angel, XL Terrestrial.
This is the second time the HIVE is shown. First being in "Final Exam."
This is the first time we are addressed with the Cyborg / Jinx relationship. There are hints of it in later episodes.
This episode marks John DiMaggio's first appearance as Brother Blood.
Opener: The Titans fight the H.I.V.E. Five when they attempt to rob a place of its gold.
When Gizmo traps Robin, Starfire, Beast Boy, and Raven in the final fight, he traps them in the exact same orange bubble type forcefield that Atlas used on them in "Only Human."
Look Hard: One of the HIVE students looks a lot like the alien from Warp Trek V, mentioned by Control Freak in "Fear Itself."
When everybody laughs at Stone, one of them is character designer Derrick Wyatt.
Look Hard: One whole block of HIVE students seems to be based on Batman, Wonder Woman, Green Lantern, and Flash.
Look Hard: When all the HIVE people are laughing, you can see the actress from "Fear Itself" laughing.
Look Hard: When everyone stares at Cyborg in the cafeteria, you can briefly see Seemore from "Mother Mae-Eye" sitting next to Bumblebee, and on the other table you can see Billy Numerous from "Overdrive." Both are without dialogue in this episode, but can be seen at different points in the episode.
Look Hard: When the other HIVE students are laughing at Cyborg, a.k.a. Stone, you can see one of them is a girl wearing a cloak that looks exactly like Raven, except with a HIVE insignia on her chest.
Villain(s): Brother Blood, Jinx, Mammoth, Gizmo, & Stone.
The original headmistress of the HIVE Academy from "Final Exam" is seen as a "missing" picture on Stone's carton of milk during the cafeteria scene.
Look Hard: One of the background HIVE students looks like M.O.D.O.K. from Marvel Comics.
YTV airdate: November 19, 2004.
Robin uses two half-sized bo staffs. As the bo staff was the third Robin, Tim Drake's, main weapon, the short bo staffs are a reference to the original Robin, Dick Grayson, who, after becoming Nightwing, uses escrisma sticks and tonfas.
We see a parody of Batman at the HIVE.
In "Final Exam," Gizmo, Mammoth, and Jinx use "Attack Pattern Alpha." In this episode, they use the same technique, plus another strategy called "Attack Pattern Gamma." (They must name all of their strategies after Greek letters.)
Bumblebee, a Titan from the comics, makes a cameo at the H.I.V.E.
Cyborg's disguise name, "Stone," is a play on his real name, Victor "Vic" Stone from the comics.
Stone: The Thing
In this episode, Cyborg has a secret identity - Stone. Stone is very similar to a character known as "The Thing." In the cartoon series, The Fantastic Four, "The Thing" was actually a kid named Benjy Grimm, who used two rings to transform into his orange rocky alter-ego, "The Thing."