Goofs

In the news sequence near the end of the film, one of the scrolling headlines says "Spurs win Champions League Final" and then another says "Battle for Xmas No.1 hots up". The Champions League final is always in May, so it's unlikely that the news for that day would contain anything about the Xmas No.1

When Ewan cuts the detonator wire with the knife, he cuts both wires at once. This would short the wires through the blade and set the bomb off.

If that had been the detonator wire, this would be correct. What he cut was the wrist lanyard that was preventing the detonator from being dropped.

When we see the newspaper article with the headline about the graduate dying in the bomb attack, most of the text is actually about Great White sharks being spotted off the coast of Cornwall due to global warming.

When Tuppence Middleton is in the shower, she is wearing a pastie.

Both Ewan and Mark have silenced pistols outside, but as they walk inside the house, their pistols are seen without silencers. Later in the same scene they both have silencers back on their weapons.

When Harry is leaving the Mayfair he is attaching the buttonhole to the left lapel. When he enters the street he is holding the buttonhole. Whilst being chauffeured to the next hotel he is trying to attach the buttonhole to the right lapel. When he reaches the new hotel the buttonhole is now on the left lapel.

When Ewan is hit with the fire extinguisher, his stunt back protector is visible. In the next shot it is gone.

(at around 46 mins) Ash is in a white van with his accomplice. Just after Ash says "follow them" the scene switches briefly to the side of the van. You can see the tripod, camera and crew in the reflection of the white van.

Amin mocks Ash for eating with a knife and fork, calling him "English man" and making a point of eating with his fingers. But Amin eats with his left hand; Islamic custom dictates only the right hand should be used for eating.