Visible crew/equipment: When Wally and Beaver go downstairs to tell their parents about being at court earlier, Wally stops at the edge of the rug and his curved chalk mark is visible on the bare floor. (00:22:15)
Visible crew/equipment: When Mrs. Bennett shows up the second time and tells June that she'd like to give Beaver a reward, the curved chalk actor's mark is visible on the floor near the staircase, and it's where June will stand after Poncho and his "mother" leave the house. (00:21:05)
Captain Jack - S1-E3
Continuity mistake: Where's the puppy that the boys get at the end of this episode throughout the rest of the series?
Suggested correction: In episode 1x23, Beaver and Poncho, when Beaver brings home a lost little Chihuahua, he shows his parents and asks to keep him. Then Ward tells him, "You and Wally had a dog once, remember? You didn't take care of him. We had to give him away." This explains what happened to the dog from 1x3.
Visible crew/equipment: In the opening, the camera boom shadow is visible on the door after June enters and Ward enters.
Other mistake: In the opening, when they get into the car, it's obvious that there is no glass in the rear window.
Other mistake: In season 1, we learn that Beaver is in 2nd grade-Wally in 8th. So by the end of 6 seasons, Wally would be in college. Tony Dow and Jerry Mathers are actually 2 years+/-apart.