Corrected entry: This episode takes place during the holidays and Robin is missing her family. At the very end of the episode Robin and Marshall are sitting outside - Robin is eating an ice cream cone and Marshall is drinking an icee, and they are both wearing T-shirts. Behind them are poinsettia plants and they mention Christmas in the episode. They live in New York. It snows in New York during the holidays or is at least cold. They would not be wearing T-shirts sitting outside on the stoop eating ice cream.
Corrected entry: Barney drives fast to prove to his friends that he can talk his way out of a ticket, however in the earlier seasons, when Marshall's car broke down, they tell a story about Barney driving and he cannot drive, and seems to have a fear of driving.
Corrected entry: In this episode they call Barney's mom "Loretta", but in the 10th episode of the 3rd season, "The Yips", Rhonda "Man-Maker" French calls her Patty.
Corrected entry: When Barney invites Lily to his house Lily says he called her at 7:22 am, but when the camera shows Lily it shows 19:47, which means 7:47 pm, not am. (00:02:25 - 00:09:30)
Right Place Right Time - S4-E22
Corrected entry: When the first error in Barney's list is discovered, they come to the conclusion that he's only slept with 198 women, so Marshall's previous figure of a 1.195913451538% success rate is slightly off. Marshall says that Barney's "only half a percent less gross than we thought." But using 198 girls in Marshall's equation results in a success rate of 1.18990461538%, which is nowhere near a difference of 0.5%.
Correction: 1.1959% minus half a percent is 1.1899%, ie. fitting exactly with what Marshall says. Subtracting 0.5 wouldn't be half a percent, as 0.5 is a large proportion of 1.1959 (42%, in fact).
Corrected entry: The Marshall/Lily plotline revolves around Lily's bringing Marshall a six-pack of beer from every trip. But the FAA ban on liquids and gels on aircraft would have ended that tradition several years ago.
Correction: This does not have to be true. If she buys the beer after she is through the check point, (eg from duty free or other store in the airport) she could have it on the flight with her.
Corrected entry: In episode 3-4 "Little Boys", there is a flashback of Robin as a young girl, with girly clothes and long hair. But in this episode she says that her father raised her as the son he never had.
Correction: Not to the absolute literal sense. She was raised doing male/boy hobbies and interests but that doesn't mean she always looked like a boy.
Many flashbacks including her with her father have included short hair.
Corrected entry: There are two problems with the scene in which Heather enters the store with the briefcase. One is debatable, but one is not. All stores, for safety reasons (most notably, if a fire were to break out) should have doors that open outwards, away from the store. It's a law in most areas of the US. The other thing is that Ted says, "That's a "push," not a "pull."" That means that she attempted to pull it, but if it were a "push" door, there would be no handle to pull, meaning there is nothing there for anyone to pull on.
Correction: No they are both debatable. There is nothing wrong with having handles on both sides of the door. No mistake here. As for the 'safety' concern. You said 'most areas' of the USA have this rule. Can you tell me that every store in NYC abides by this rule? I would imagine there would be a lot of stores that don't, this store for example. No mistake here.
Corrected entry: Ted thinks he's texting Holly, when they're actually going to Barney's work cell, as he explains to Robin. It therefore makes absolutely no sense that Ted would get the text about the restaurant that Marshall would have sent to Lily.
Correction: These two are unrelated to each other. Marshall just mis-sends the text.
Right Place Right Time - S4-E22
Corrected entry: At the end of the episode when Ted goes around hugging people whilst holding the yellow umbrella, he isn't holding the umbrella when he goes to hug Barney at McLarens.
Correction: There is a place to check umbrellas at the entrance of the bar, so Ted must have checked it like everyone always does. Notice how even when it is raining, no one has umbrellas in the bar.
Corrected entry: When Lily walks into MacLaren's at the end, you can see her pregnant belly bump due to Alyson Hannigan being pregnant during filming. Lily was not pregnant at any time during this season. Even if she did try to cover it up with her coat, the belly bump is still visible. (00:20:25)
Correction: It's passed off as her eating too much and getting bloated.
Correction: The episode makes repeated references to the fact that they are from colder areas (Canada and Minnesota). As such, neither find the winter climate in New York particularly cold, something that is exaggerated to the point of them behaving as if it is summer weather. It seems you missed one of the key jokes in the episode.