Deliberate mistake: When the Looney Tunes are playing basketball against the aliens, if you look in the stands the same cartoon characters are in different places at the same time. This happens a lot.
Space Jam (1996)
1 deliberate mistake - chronological order
Directed by: Joe Pytka
Starring: Billy West, Wayne Knight, Theresa Randle, Manner Washington, Michael Jordan
Other mistake: Near the end of the closing credits, when the Warner Bros. Copyright appears, you'll see the very first word "All" spelled incorrectly as "Al" in "All material is protected by Copyright Laws of the United States and other countries throughout the world." (01:26:40)
Stan Podalak: Let me help! Let me help! I can help! I can help!
Michael Jordan: What can you do?
Stan Podalak: Well, I may not be very tall, but... I'm slow.
Sylvester: And large.
Daffy Duck: And a dork.
More trivia for Space Jam
Question: Are all the characters in the crowd at the Basketball game from the TV shows or were some made just for the movie?
Answer: These were all actual characters from Looney Tunes.