Continuity mistake: Back at the post office/sweets shop, Howie witnesses a bizarre bit of 'traditional medicine' involving a frog. The animal is held in close-up in a different way than in the first shot - the position of the last 3 fingers changes. Moreover, despite the spoken lines overlapping between shots giving the impression of continuity, the candy jar appears out of thin air, since the woman had just barely put the frog away in the other box.
Continuity mistake: Sergeant Howie is being quite critical about the food quality at the inn. Willow tells him that he can have "peaches and cream", and he replies "Aye, from a can I suppose." The beer fills his mug up to the top section of the handle. Brief cut to Britt Ekland, and in the next shot Howie's mug is half empty even if he didn't have time to drink - nor it is implied he moved at all, the position is the same.
Continuity mistake: Sergeant Howie cuts short the bawdy song at the pub banging an ashtray on the counter. You can then notice that in the wider shots the scarf at the neck of the owner of the pub is positioned differently compared to the closer views; a bit of it is untucked/tucked into the collar.
Continuity mistake: After the part when the song mentions the 'toes' of the Landlord's Daughter, there's a bit when a burly bearded man gets behind Willow and bumps his large literal pouch against her rear, performing pelvic thrusts while his hands are kept at the height of his shoulder. Cut (during the song, played continuously) and his hands are joined above his head.
Continuity mistake: During "The landlord's daughter", the protagonists starts to realise something is quite a bit weird once one of the patrons mentions the parts that stand 'at attention'. In the background, Willow's dad walked to the right and is facing away from the crowd, but in the next close-up on Edward Woodward, he's behind him and smoking facing him.
Continuity mistake: In the extended version of the film, in the scene at the police station, Officer McTaggart is reading the letter to Sgt. Howie about the missing girl on Summerisle. There's a photo of the girl included with the letter, which McTaggart holds in his right hand to look at. The next shot is a close up of the photo, which shows it being held in the left hand. The next shot of McTaggart holding the photo again shows the photo in his right hand.