Helen hands Goober a bowl of pretzels from the coffee table. In the wide shot, he is holding the bowl and they are gone from the table. But a moment later, in the close-up shot of Helen, Andy, Barney and Thelma Lou, they are back on the table. A moment later, they are still in Goober's hands.
When Goober and Lydia show up at Helen's house, stairs are visible behind Andy, Helen, Barney and Thelma Lou. In the wide shots, it's evident the stairs don't go anywhere. They are blocked by plywood.
When Goober and Lydia arrive at Helen's house, Andy introduces Lydia to everyone, including Thelma Lou. But in Barney Mends a Broken Heart (1962), when Thelma Lou and Barney tried to fix Andy up with Lydia, she was introduced to Andy as Thelma Lou's friend.
Andy asks Barney if he knows Lydia Crosswaith, but Andy would already know that Barney knows Lydia, because Barney and Thelma Lou brought Lydia to Andy's house in Season 3, Episode 6, "Barney Mends a Broken Heart."