The Ornithophobia Diffusion - S5-E9
Factual error: Sheldon is fearful of the bird on his windowsill, which he identifies as a blue jay. Blue Jays are not native to CA. The bird is actually a scrub jay. Sheldon would know this because of his lifetime fear of birds.
The Ornithophobia Diffusion - S5-E9
Continuity mistake: When Leonard and Penny are at the movie theater the same couple walks behind Leonard, twice.
Chosen answer: It does. The variable cleanliness of the cab and the habit of taxi drivers to engage customers in small talk would be too much for Sheldon to handle, and not an option for him.
Captain Defenestrator