Continuity mistake: When Mr. Feeny is asking the class if they have any comments on Cory's documentary, he calls on Angela, and Cory begins turning his head to look in her direction. When the shot changes, he is instantly looking at her. (00:04:12)
Other mistake: When Cory goes into the apartment and starts to film Shawn and Jack fighting, he is sitting on the coffee table behind them. When what Cory is filming is shown, the camera is facing their sides, not their back. (00:10:47 - 00:11:11)
Continuity mistake: In this episode Eric said he was 8 months older than Jack, but in '5-17 And Then There Was Shawn', Jack said that he was older.
Continuity mistake: When Topanga is in the elevator and is saying "We'll just have to let nature take its..." the elevator door completely closes before she can say "course." When the shot changes to Cory saying "Nature take its what?", the door can be seen sliding closed again.
Other mistake: As Wendy is leaving the apartment, she writes her phone number on Shawn's palm and tells him to call her. She only scribbled a few lines on his palm for a second, not nearly enough time to write her entire phone number down.
Continuity mistake: When Cory is whispering in Amy's ear, she is holding a cup of frozen yogurt in her left hand. When the shot changes, she is holding it in her right hand. (00:16:40)
Continuity mistake: If you look in most of the scenes, especially the one where she is throwing the stuff out the window, you can see a wall out of the window, but in the scene where Cory comes back from seeing the lady you can see a dresser out the window.
Factual error: When Shawn has first infiltrated the college philosophy class, the professor begins to resume the class' previous lesson on what he calls "Buridan's paradox," relating a dog caught equidistant between two bowls of food. This paradox in real life is known as "Buridan's ass," and as the name would suggest, concerns a donkey. While the name was probably changed to sound more family friendly, a college philosophy professor would certainly know the proper name and details of said paradox.
The Witches of Pennbrook - S5-E5
Continuity mistake: When Shawn is saying "So, Rosemary, how's the baby?" his left hand is resting on a box of household items. When the shot changes, his left hand is instantly raised. (00:10:00)
The Witches of Pennbrook - S5-E5
Plot hole: In this episode Cory takes Topanga on her "first airplane ride". But in season three (episode 66), Topanga had to go Disney World and she obviously took a plane.
How to Succeed in Business - S5-E9
Continuity mistake: When Amy shows up in Eric and Jack's creative writing class, her backpack is first shown to be unzipped a few inches wide, and just before she sits down, it is suddenly zipped nearly closed. (00:06:20 - 00:07:00)
A Very Topanga Christmas - S5-E11
Continuity mistake: When Topanga tries the egg nog, you can tell that there is nothing in the paper cup.
A Very Topanga Christmas - S5-E11
Character mistake: When Cory is talking to Alan in the middle of the night, he mentions that Topanga has been staying with them for less than 8 hours. She arrived during the day time, and then convinced the family to go to Vermont to get a real Christmas tree, which they are cutting down at nighttime, and Eric later expressing after the new tree has been put up and decorated that it was 600 miles round-trip. All of this would take more than 8 hours. Driving from Philadelphia to the southernmost part of Vermont and back again alone would take more than 8 hours.
A Very Topanga Christmas - S5-E11
Other mistake: When Topanga knocks on Cory's door at 3:00 AM, he comes out and expresses that he's always asleep at this time of night. Despite this, he shows no signs of having just been awakened from his sleep. On the contrary, he appears very alert.
A Very Topanga Christmas - S5-E11
Factual error: This episode takes place near and on Christmas, but an establishing shot of the Matthews' house early in the episode shows the trees to still have very green leaves, and outdoor plants and the front lawn are still alive and healthy looking. None of this is possible in winter in Philadelphia.
Raging Cory - S5-E12
Continuity mistake: When Jack is sarcastically asking Shawn if his room is where what people throw down the garbage chute ends up, they are standing shoulder to shoulder. When the shot changes, there is now space between them. (00:02:25)
Raging Cory - S5-E12
Continuity mistake: When Shawn is talking about how the time Cory beat up his dad will be a great memory, the half of a cracker he is eating suddenly has another half-sized bite taken out of it and his hand is near his mouth. When the shot changes, the cracker is half-sized again and his hand is several inches away from his face. (00:03:40)
The Eskimo - S5-E13
Continuity mistake: When Jack is asking Eric about his date the previous night, Eric puts down the book he was reading with the spine facing towards Jack. When the shot changes, the book has now rotated almost 90° counter-clockwise. (00:03:56)
The Eskimo - S5-E13
Factual error: When Shawn and all the other contestants - as well as the radio DJs and onlookers - are standing out in the cold for a chance to win Super Bowl tickets, no-one's breath is visible, nor are any parts of their faces red.
The Eskimo - S5-E13
Other mistake: When Shawn is saying "Thanks a lot Topanga" after she falls to the floor, he is looking down directly in front of him, but she is to his left.
Answer: Topanga's middle name is never specified. Considering her sister's name is Nebula Stop-the-war Lawrence, Topanga's is probably something equally unusual.