Continuity mistake: In the pilot episode we see the Son and Daughter listening to the start of the story on how Ted met their mother. In the final episode of the show it's revealed that the whole story has taken place in one sitting. However, the clothes the kids are wearing and the items around them are different in the pilot episode to every other episode. The sofa is a different design, the cushions appear etc. (00:00:45)
Continuity mistake: Before Marshall proposes the gold foil is still on the bottle of champagne. He sets it down with the foil still on and they have sex on the kitchen floor. When they sit up, he grabs the bottle of champagne again and the foil is already off. (00:04:50)
Character mistake: When they see Robin on the news at the end she says "Metro 1 News" instead of "Metro News 1". (00:12:20)
Other mistake: At the beginning of the series, Ted starts telling the story of how he met the mother of their children. When he starts describing how he met Robin, he doesn't reveal that it was not their mother until the end of the pilot. But children should have realised it wasn't their mother when Robin said she was a journalist and worked as a TV presenter. The kids knew their mom wasn't a journalist, so they shouldn't have been surprised at the end of the episode when Ted said "this is how I met your aunt Robin".
Continuity mistake: The foam on top of the drinks Barney puts down at the start changes drastically between shots. (00:01:50)
Continuity mistake: In the opening scene at the bar, the level of beer in Ted's glass goes up and down between shots. (00:02:30)
Continuity mistake: In the opening scene at the bar, when Ted is debating whether or not to ask out Robin, Marshall's beer is in his hand when the camera is on him, but on the table when the shot is from behind him. (00:03:00)
Continuity mistake: When Ted mentions having a party, Marshall's hand goes from on his beer to on his chin instantly. (00:03:10)
Continuity mistake: Barney tells Lily that she's rubbing his leg. When he does, a wine glass suddenly appears in Lily's hand. (00:03:20)
Continuity mistake: When Barney is explaining about there always being 1 girl who doesn't know who's party it is, his hand is sudden;y outstretched or by his side depending on the shot. (00:08:00)
Continuity mistake: When Barney is scoping the apartment, his hands are next to his temples. As the shot changes to a wider shot, they are now much further away from his temple. (00:08:05)
