Sammo Blammo - S2-E1
Continuity mistake: In the scene at the bank, he has a bomb attached to him and an ex-bad guy handcuffed next to him, the handcuff is roughly a foot long, making the distance short between him and the guy next to him. Sammo fights a gang of thugs in the bank and does a swing round kick and his handcuff is detached or widens by 3-4 ft. The guy on the floor is rolling around to make it look like he is attached to Sammo, but is clearly not.
Plot hole: During the episode "Superstition", Onizuka thinks he has cancer because the magnetic pain-pads he was wearing created strange blobs in the X-Ray he has taken. However, given the fact that the X-Ray was so strange, doctors would have given him a complete physical, and noticed the pads much sooner. Here, they literally just assume he has tumors, and fail to ever take notice of the pads. Simply impossible, given the gravity of the situation. (Obviously, this is to pay off at the very end of the episode.)
Learning Curve: Part 1 - S1-E5
Factual error: When Pip is blasted back by the plasma jump, he is shown to rotate his body and slow down just before Silver Surfer reaches out and grabs him. Since he is in the vacuum of space, no amount of adjusting himself would help him slow down. He would continue to float perpetually until he bumped into something with more mass than himself or entered the atmosphere of a planet.
Continuity mistake: In the episode "Fool's Gold" Debbie puts the fool's gold on top of the pail on her sculpture. The shot changes and it's gone, the next shot it's back.
Character mistake: When the gang is watering the horses, Chris walks over to meet Mary's man friend (whom she introduces as an old friend of the family) and the mystery man tells Chris that he'd proposed to Mary long before 'Frank' when Mary's late husband was Steve.
Visible crew/equipment: In the episode where they are planning Karl's sister's wedding, when Karl is in the kitchen, right before Vigdis enters, you can see a crew member in a red t-shirt reflected in the glass door of the storage unit behind Karl. This crew member can be seen several times throughout the scene.