Freshman Orientation and the Inventor of the Zipper - S4-E6
Plot hole: Memaw gets a call from Dr. Sturgis saying that he has moved to Waxahatchie and would she please call him back. He does not say the new phone number, and this was well before cell phones were in widespread use by the general public, so it could only be a land line. Memaw calls him back, although she could not know the number.
Suggested correction: Memaw could have caller ID, or she could have called information.
Caller ID was first available in December 1988, and it's unlikely that Memaw would have it that early. The story takes place before that time. It is possible that she called information, but when did she do it?
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.