Character mistake: When Grandad collapses, the Doc calls Morwenna's grandfather Mr. Dunwich, which is the surname of one of his patients in this episode. The grandfather has the same surname as Morwenna, which is Newcross.
Character mistake: When Bree calls the police when she hears a noise downstairs, she says she lives at 4355 Wisteria Lane when her address is in fact 4354 Wisteria Lane. 4355 is the Scavo residence, not the Van De Kamp residence.
The Peruvian Puff Pepper - S3-E2
Character mistake: Drake says he hasn't been in Megan's room since he was five, but he brings Grammy's bags up there in the episode "Grammy".
The Purple Panther: Part 1 - S3-E6
Character mistake: In the song 'The World Goes Round', Stingy sings about dinosaur bones from the Stone Age (the second verse). The dinosaurs were wiped out about 65 million years ago while the Stone Age started 2.5 million years ago, an obvious time gap.
School Elections & Talent Show - S1-E8
Character mistake: There is a campaign poster that reads, "Vote for Ned or Your Dead." "Your" should be spelled "You're."
Character mistake: Sasha refers to the 'murder' on Thursday 4th June 1982. The date in question was on a Friday.
Character mistake: Sue White suggests speaking in Portuguese but what she says next is actually Spanish. (The subtitles incorrectly say she is speaking Portuguese). (00:04:00)
Character mistake: Lorraine mistakenly tells Denny to "call 999" instead of 911, and when asked about it by Katie, denies having ever spent time in the UK (later revealed to be a lie). But this isn't some high-pressure slip of the tongue, she's highly intelligent and has been in America for a decent length of time, is working hard to maintain her facade of being born and bred American, so there's no way she'd slip up over such an obvious thing.