When Leela is walking the cat on the treadmill, her pupil is dilated (Meaning she was being hypnotized) However, the next shot shows her eye normal.
When Amy is crying because she invented the ratchet, she cries vapor (due to the increased temperature) though tears are salt water, and when salt water evaporates, it leaves salt crystals, so she should be crying vapor and salt.
Towards the beginning of the episode, Leela is disposing of Nibbler's litter box in the volcano Amy is doing testing on. Leela refers to the waste as "highly volatile dark matter." Dark matter was rendered useless at the end of Bender's Game.