Plot hole: When Jeremy stopped to drink his water, which turned out to be vodka and which killed him via a heart attack, why did he hide himself away, surrounded by plants and only found by his mobile ringing? And why would he put the lid back on the bottle in the throes of a heart attack?
Plot hole: When Eddie finds the hammer that killed Cousin Jim, Rosemary and Laura are on his tail, so he rushes to the river, and so does Martin and the constable. Problem is: Eddie and the girls are on one side of the river and Martin and the constable are on the other side of a river that is impossible to cross where they are - there are bridges, but not there. So, if Martin and the constable were heading for the hammer, why did they go to the wrong side of the river? It's all very dramatic, as Eddie has to dive into the water, but it's ridiculous, plot-wise.
Plot hole: The girls refer to Holly's owner as Mr Volker, even though they now know her owner is Mr Allbright. For plot reasons, they have to say to Sherry that Mr Volker is Holly's owner, because now she knows she's killed the wrong man, and she'll have to kill again.
Plot hole: At the very end, Julia calls Matt, a policeman, at Helena's place, to tell him to come and help his mother and Rosemary who are being held against their will. But Matt doesn't have a mobile, so how did Julia know he was at Helena's place, so she could ring him there and save the day? No-one knew he was at Helena's and it's the middle of the night. Matt should have been in bed asleep.
Plot hole: When Jeremy is found dead from a heart attack, for some reason, the girls talk about him taking something that caused his heart attack, or someone giving him something to cause his heart attack. People have heart attacks all the time, and Jeremy had "a dodgy ticker", so there's no reason for them to only think it's a "suspicious" heart attack.
Plot hole: When Daisy is killed, Dan comes around to collect her things. So we'll be able to see him reading one of Daisy's love letters from Ben and accuse Ben of Daisy's murder, when Dan takes the box from Stuart, who is holding it with his hands underneath, keeping everything in, he holds the box with his hands on the side, deliberately, so the love letters fall out to the ground - and how convenient that nothing else falls out, just the love letters. But the letters were written before the girls arrived - they saw them - so how could Dan accuse Ben when the blue one has Ben asking Daisy to meet him in the summer house, but it was days ago, not relevant now.
Plot hole: When Rosemary discovers the side door to the church and a plastic knock, from an arrow, on the floor, she jumps to the conclusion that the arrow was shot from the side door. This all makes sense - this knowledge is how they catch Mr Danvers - but there are too many branches from the Yew tree to make this possible.
Plot hole: Dan, the policeman, finds a love letter written by Ben to Daisy, Dan's sister. The letter says "Meet me in the summer house tonight." When the girls arrived 2 to 3 days ago, Ben and his brother were arguing about the letter, which was written on blue paper. When Daisy is killed, Dan, ridiculously, accuses Ben - only on the blue letter as evidence, which we know was written days ago, and Daisy was killed in the afternoon, not at night as the letter says; plus, Dan says Daisy was struck with a heating tube, just like the ones where Ben works on the winery, but anyone could have picked it up. The evidence is stupid, but Ben is arrested, placed in handcuffs and taken away.
Plot hole: While the girls are trying to work out who killed Jeremy, Rosemary says she thinks it's Julia - Julia owns the flat that Jeremy and Marcia live in - so Laura says "Why would she want Jeremy dead?" And Rosemary says "To sell the house for a greater amount of money." But that's wrong: When someone dies in a house, the house sells for less, not more - not many people want to live in a deceased estate.