Episode XX - Jack and the Monks - S2-E7
Revealing mistake: Immediately after the time portal is destroyed, it stops raining but there is no moisture anywhere.
Piemanmoo
14th Apr 2004
Samurai Jack (2001)
13th Nov 2003
Samurai Jack (2001)
Episode II - The Samurai Called Jack - S1-E2
Revealing mistake: When Jack cuts the flying car's hood off, he slashes it vertically, but it is cut horizontally.