Factual error: Sheldon says the movie Gremlins "baffles" him in regards to the instructions being very clear."Don't feed the gremlins after midnight." However, this instruction is only for caring of a Mogwai, not gremlins (the gremlins are formed by Mogwais eating after midnight). Sheldon, of all characters, would not mistake Mogwais for Gremlins and he would know the exact wording of the instructions.

The Big Bang Theory (2007)
1 factual error in The Pirate Solution - chronological order
Starring: Kaley Cuoco, Johnny Galecki, Melissa Rauch, Simon Helberg, Jim Parsons, Kunal Nayyar
Genres: Comedy
The Countdown Reflection - S5-E24
Factual error: There is not a snowball's chance of Howard becoming an astronaut. He suffers from cardiac arrhythmia, something about which he is completely open. "Transient" or not this is easily detectable by a simple electrocardiogram, which is a fundamental part of the many medical examinations a potential astronaut will have to pass. He wouldn't even be allowed to start basic training. Note also that during his basic training he shows signs of severe stress and trauma which would inevitably trigger a cardiac episode. Even if it didn't the fact that he was falling apart at the seams would have him removed from the programme for his own good.
The Big Bran Hypothesis - S1-E2
Sheldon: Oh Gravity, thou art a heartless bitch.
Trivia: During Season 3, the producers learned of a show called "The Theorists" in the country of Belarus that was a copy of this show. A lawsuit for copyright infringement would have been pointless since the production company for "The Theorists" was owned by the Belarus government. A lawsuit, however, was not needed because when the actors and actresses found out the show was a rip-off this one, they promptly quit and "The Theorists" was cancelled.





Answer: Because Raj's selective mutism seems to be caused by women that Raj sees (on some sort of conscious or subconscious level) as a potential sexual partner. An attribute that wouldn't apply to either his sister or mother.