Factual error: In the episode where Sydney is supposed to be in Helsinki, there are visible skyscrapers in the background. There are no skyscrapers in Helsinki.
Day 4: 2:00 P.M.-3:00 P.M. - S4-E8
Factual error: When Edgar proves that Mary-Ann Taylor framed Sarah to be the rat in CTU, he claims that she remotely took control of her computer by sending the signal over "a plain old AC power line." This is not possible, unless the computers were equipped with special hardware to separate the AC from the signal. If they were, this traffic would have been observed by James Heller's assistant.
Factual error: Even though the show is called "Samurai Jack", Jack isn't really a samurai. The correct title for him would be a Ronin as a Ronin loses their master if their master dies or loses favor with their master and also has no home anywhere. Jack has these attributes. He has no master and no home.
Suggested correction: Nor is his name really Jack. "Jack", and thus "Samurai Jack", is just an alias that the prince takes. It's not meant to be his title or rank. Just like Cowboy Jack wasn't actually a cowboy.