Revealing mistake: The mice on the table are in slow motion. What's more, you see the same shots of them several times.
Audio problem: When Deep Thought is describing how he's going to create a new computer, he describes it as "a computer that can calculate the answer to the ultimate question." This is wrong: Deep Thought himself just did that. The new computer is supposed to calculate the question, not the answer.
Chosen answer: That seems to be an error in the subtitling of the episode. What Marvin actually says is: "I may just be a menial robot, but I'm far too intelligent to expect to think of me for a moment... far too intelligent..."
Sierra1 ★