There's No Place Like Home (2) - S5-E6
Other mistake: At the very end, Mr. Hanson is seen walking toward the church. Because of his stroke, he's slow and unsteady. We see several close-ups of his feet, showing how he's struggling. Two of those shots are the same footage. It's obvious, because you see that he drags his foot over a small stick in the road and stumbles - and in both shots, it is exactly the same.
Just a Matter of Time - S5-E13
Other mistake: In reality, Steve would radio in from the capsule as soon as he woke up on Earth, but strangely failed to do so until later in the episode.
Backlash of the Hunter - S1-E1
Other mistake: Jerry Grimes follows Rockford to the theater, sits at the bar, orders bourbon and water and waits for Jim to come out of the bathroom. Jim meanwhile set up a trap for him, which somehow does not affect anyone else, and Jerry ends up getting roughed up. He then drives off to this other joint, where he sits at the bar...which happens to be the exact same bar with the exact same posters as the other one.