Other mistake: During the fight scene in the TGRI building, when Michelangelo has the ooze and gets jumped for it and loses it, watch the bottom of the screen. Donatello is lying down and trying to get up. But in the next shot he's up and kicks out the ooze from the foot soldier. (00:26:35)
Other mistake: The Italian version of the movie keeps the "All the good ones end in -O!" joke that singles Raphael out, making him angry and causing his punishment...but the Italian names of the Turtles ALL end in O, "Raffaello" included. (00:31:05)
Other mistake: During their computer hijinks, Leo asks Don "Can you bring up the file?", which the Italian dub mistranslates in a nonsensical "Can you block the file." (00:25:30)
Other mistake: In the TGRI building, the whole computer scene is the kind of nonsense you can expect from something really 90s and childish. Forgetting the fact that Donatello's big fingers are obviously too big to push the keys, the database screen scrolls independently from his movement, and when he tries to "decode" the database, whatever it means, he just types back the serial number. It's all just waving hands around to make it look like you're doing something. (00:25:05)
Answer: If you pay attention to the professor's explanation (starting at 0:55:55) he says "An unknown mixture of discarded chemicals was accidentally exposed to a series of radiated waves and the resulting ooze was found to have remarkable but dangerous mutanagenic properties... on our way to bury them a near collision caused us to lose one of the canisters down a sewer 15 years ago." Basically, "we had an accident and the results were dangerous and unpredictable, so we immediately went to dispose of it all." So there actually were no plans for what to do with it at all.
Garlonuss ★