Visible crew/equipment: When Tooey and Eddie come over to see Wally's "really sharp" new plaid suit, the boys go upstairs to see Wally's new crazy socks. Then, just as Ward tells June the suit looks like a horse blanket, the shadow of the moving boom mic is visible at the top right corner of the screen. (00:15:20)
Leave It To Beaver (1957)
1 visible crew/equipment mistake in Wally's New Suit - chronological order
Starring: Barbara Billingsley, Hugh Beaumont, Jerry Mathers, Tony Dow
Other mistake: The opening credits for season 5 show June coming out of the front door with a pitcher of what looks like iced tea, and calling for Ward, Wally and Beaver who are all working outside. But the door opens by itself as she comes out, and then closes by itself behind her. If the entire family is outside, who opened and closed the door?
Eddie Haskell: Look Sam, if you can make the other guy feel like a goon first, then you don't feel like so much of a goon.
Wally Cleaver: I don't get that.
Eddie Haskell: Of course you don't. That's because you never went to kindergarten with a home permanent.
Captain Jack - S1-E3
Trivia: The episode "Captain Jack" was the first time a toilet was shown on TV; the boys buy a baby alligator and Wally is shown putting it in the toilet tank. The network censors were so spooked by the thought of showing a toilet on television that they delayed the episode. And when the censors finally relented, the compromise allowed only the toilet tank to be shown, not the bowl.