in the episode "no tomorrow", the mother is shown wearing pants outside the nightclub. in this episode, she's wearing a dress.
In "The Naked Man," Robin asks Mitch what it's like managing a CPK (California Pizza Kitchen). Here, Mitch is said to be a music teacher.
They show Ted running into Tracy (aka The Mother) after the mix-up with the class. There is even more ground/open space visible. In "Definitions" he doesn't run into anyone and is only shown running from building to building.
Also, in this one, Tracy is shown in the Economics class but in the episode "Definitions" she isn't seen in the class, even though the camera eventually pans to where she would be. This scene takes place before she thinks she's in the wrong class, so the character should be present.
Also, in this one, Tracy is shown in the Economics class but in the episode "Definitions" she isn't seen in the class, even though the camera eventually pans to where she would be. This scene takes place before she thinks she's in the wrong class, so the character should be present.
Ted was wearing a sweater outside while listening to the Mother playing the ukulele, the next scene Ted is wearing a shirt.
Ted is shown running passed his future wife on campus, as he leaves the incorrect classroom he's in to run to the correct building. In reality this would not have happened because his future wife would have stayed seated, along with the rest of the students that showed up for the Economics class that was held in the room Ted was running from.
St. Patrick's Day is seen set in April 2008, while in reality, St. Patrick's Day is on March 17th. However, in later airings in syndication and DVD/streaming releases, the date is corrected to March 2008.
The scene where The Mother and Cindy meet, you can see in the background of the class that a students laptop switches from an Apple computer to a different one.
When Kelly gets into the yellow cab, it can be clearly indentified as a Ford Crown Victoria. In the next scene, the camera is following an older Chevrolet Caprice, before reverting to a Ford in the next shot.
Future Ted said after their meeting at MacLaren's that The Mother and Louis dated for a couple years. However, The Mother breaks up with Louis on the wedding weekend (May 2013) so they only dated a year if their meeting was in 2012.