Stupidity: When Donatello frees the professor, he gets his head in his visual range, and same goes for his thick inhuman hands, but he notices only when the plot says so, a few moments later. (00:52:50)
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Suggested correction: The professor is in noticeable distress, likely from having been tied up for so long and hearing the fight between the foot soldiers and the turtles occurring just outside, so he isn't paying much attention to who is rescuing him at first; he just wants his hands untied and to get the tape off his mouth.