A Roulette Wheel and a Piano Playing Dog - S7-E2
Character mistake: Sheldon likes his pretzel and says "Ich bin ein Heidelberger." He makes the same mistake President Kennedy made when he said "Ich bin ein Berliner", which means "I am a jelly donut." The correct German is "Ich bin Berliner" or "Ich bin Heidelberger."
Little Green Men and a Fella's Marriage Proposal - S6-E18
Character mistake: When Dr. Bell examines baby Constance, she has the stethoscope in her ears facing backwards. Also, when Sheldon and the professors are looking at the data from the telescope, Dr. Linkletter says "what about that" and Dr. Prakash says "no, that's within the standard deviation." That doesn't make sense.
Suggested correction: Not taking anything away from the other correction, but these are two separate mistakes put into one entry.
A Stolen Truck and Going on the Lam - S6-E16
Character mistake: Missy and Paige are stopped by a police officer "just outside Baton Rouge" But in Texas, the family is told they are outside Boca Raton.
