Corrected entry: When Sheldon realises his mistake in reading sq centimeters as sq meters he says "I am off by a factor of 10,000" when in actuality such a mistake would be by a factor of 100.
The Raiders Minimization - S7-E4
Corrected entry: When Leonard and Penny are doing the 'business' at the university and Howard knocks on the door, Leonard opens and says "hey Si" (Howard's real name - Simon Helberg).
Correction: He says "Hey, sorry," while panting - he's apologising for taking so long to answer the door.
The Hesitation Ramification - S7-E12
Corrected entry: When Sheldon comes to tell Leonard and Penny his perfect joke he is wearing a plain green T-shirt, but when Penny leaves and he begins to tell Leanord about it, his shirt now has a black symbol on it.
Correction: The symbol is there the entire time. It's just very difficult to see.
The Thanksgiving Decoupling - S7-E9
Corrected entry: Penny states that she did not know that a Vegas wedding is an actual wedding, however in season 5 episode 24, The Countdown Reflection, she states that she knew tons of people who got married in Vegas. (00:02:55 - 00:03:40)
Correction: Just because she knows people who got married in Vegas doesn't mean she didn't know the weddings were real.
The Locomotive Manipulation - S7-E15
Corrected entry: Sheldon asks whether the train carriage has "link-and-pin" type couplers, when he would know that such couplers were outlawed by the Safety Appliance Act of 1893.
Correction: It would easy for Sheldon to ignore this fact when he is aboard a train that has been restored to its original design; internally and externally. He has been building toy models since he was a kid. He just wanted to know to what level this train has been restored.
Correction: No, he's right - 2cm x 2cm (for example) would be 4 sq cm. 2m x 2m (200cm x 200cm) would be 40,000 sq cm - off by a factor of 10,000.