Episode #3.2 - S3-E2
Continuity mistake: Dalton and the terrorist are fleeing from the building when Locke arrives and hits the terrorist who has backed into the street with his car, thereby saving Dalton. The terrorist flies over the hood and lands behind the car in the street, never going anywhere near the driver's side of the car. Locke reenters his car to a broken driver's side mirror.
Continuity mistake: During the final shootout scene, Dan hides behind a Mustang when the redneck truckers are shooting at him. The right front tire gets shot out, and the car drops on the rim. The shot cuts to Dan, and the car's right front tire is again shot out. It is not a different view of the shot, it is supposed to be continuous action.
Continuity mistake: Mel knocks Dylan's mail onto the floor. The shot changes and some of the mail is back. Later on in the scene all the mail is gone again.
Continuity mistake: Jack rushes in at night to save Kate who has been drugged by the evil professor. Jack resuscitates her and calls an ambulance. When the ambulance leaves it is bright daylight.
Continuity mistake: When the hostages try to get some rubble to catch fire, they find that everything is covered in some flame retardant stuff. Yet, in the very first episode one of the very first things they do is to make a small fire to get the fire alarm going.