Toward the end of the episode when Don and Raph are walking down the hill after the explosion, their belts disappear and after that the lower line across their plastron that is usually hidden by the belts disappears too.
Even though Leo appears in this episode, he isn't part of the action, nor does he do any fighting.
Don's bo staff both disappears and reappears throughout this episode. He is shown to not have it at the beginning of the episode, yet he is later seen fighting with it. Also, when Don leans out of the doon buggy, we can see that he does not have his staff. The shadow he projects on to the truck however, clearly shows that he has it with him even though he doesn't have it after he climbs into the truck.
The man wielding the rocket launcher isn't too bright. He was trying to kill the Turtles from a close range with the rockets, which would have killed him also.
Baxter Stockman, in the Utrom robot body, makes a cameo appearance in Leatherhead's hallucinations. Nice attention to detail since that is how Leatherhead would remember Baxter, and not as the disembodied brain he would become.
The hunter appears to use infrared to track the Turtles. Turtles are cold-blooded, and normal infrared wouldn't pick up their body heat. Unless he uses modified equipment, or their mutant nature gives them mammalian body temps....
At the very beginning, just after Leatherhead breaks the teapot, he puts his tail flat on the ground. However, in the next second, you can clearly see a second tail being lifted off of the ground, while the original is still there. The "goof" tail then disappears behind Leatherhead's back.
When Mike first storms his way into the hotel room where Hun, Touch, and Go are talking, he knocks Hun into Touch and Go and sends all of the money in the suitcase flying. But later, he picks up the suitcase, which is supposedly filled with all of the money. Yet, as he and Splinter are walking away, there is still tons of bills lying all over the floor.
Also, when Mike is looking out the broken window, we see he is talking with Hun who is hanging on to the windowseal. Hun looks pretty angry as Mikey insults him, then walks away. Now Hun is supposed to be a pretty strong guy, so why couldn't he simply pull himself up and back through the window and go after the two mutants? Was he simply too heavy to do so or something?
When the turtles, Splinter, April, Casey, and Leatherhead visit the Triceraton Homeworld at the end to witness Traximus blowing away the Prime Leader's throne, they're not wearing atmosphere converters like they did the other times they were there. Nor are any of the Triceratons wearing spacesuits. SOMEBODY shoulda been suffocating in a poisonous atmosphere, but despite requiring wildly different gas mixtures, everybody seemed able to breathe quite nicely.
April's first aid training is about 20 years out of date -- the Red Cross now recommends that the Heimlich maneuver be performed on a drowning victim (to clear the lungs) before CPR.
-When Splinter, Casey, and April are standing in front of the laser barracade, Splinter is clearly holding a red spray canister in his right hand. However, in the next shot, the canister magiacally disappears, but reappears again when Splinter pulls it out of his coat.
During the scene where Master Splinter is freeing Raphael from his body restraits, it is clearly shown that only the arm straps were cut. This left the leg restraints remaining, though they appear broken in the next shot as Raph steps off the table he was tied to!
The Turtles end up keeping the cruiser they stole from the Prime Leader, but it hasn't been seen since the following episode.
The Earth launched its entire nuclear arsenal at the Triceraton home world and had it contained by the Triceraton force shield. Wouldn't there be some serious radioactive fallout?
In season 1 episode 4, Meet Casey Jones, the episode begins with Mikey and Raph sparring. Mikey is seen having the upper hand until Raph losses control of his temper. This reflects the idea that Mikey does have the skill to challenge Raph.
Of the contestants, Leonardo is the only one who did not have a fair shot at winning the Battle Nexus championship, something no-one, including Leo, ever mentions. Usagi's chance was also ruined since the Gyoji implied that he might have been the one to unfairly injure Leo, thus disqualifying him. We don't know what would have happened if either of these two had had a fair chance to win.
Mikey may not have literally kicked Raph's butt, but he did it figuratively by knowing his brother well enough to know that if he egged on Raph, he would basically defeat himself, saving Mikey the trouble.
At the end when the turtles and Master Splinter are back in the lair, Raph tells Mikey that he only won the championship on a technicality and Mikey says "Technically, I kicked your butt in one of the bouts remember?"
Here's the goof: Even though Mikey triumphed over Raph, he never kicked Raph's butt.
According to Turtles in Space (and later Rogue in the House), Triceratons breathe a mixture of nitrogen and sulfur. Since there doesn't seem to be an atmospheric converter hooked onto Traximus, it can only be assumed that the Nexus has some sort of universal atmosphere.
The chain-wielding warrior lost in the first one, but he can be seen fighting in the second round instead of his opponent.