When he's returning the shotgun, Chris stuffs his pockets with the jewels and drugs of Mrs. Eastby, his pockets bulge to a degree. Moments later, when he enters the study for Chloe's announcement, his pockets are entirely empty.
When Chris and Chloe meet Tom and Nola at the bar, Chloe stands up to greet the other couple, leaving a champagne cocktail on the bar, which disappears in the next shot.
When Tom picks up Chris and Chloe, he gets out of the car wearing only a shirt. When he gets back in the car, he is wearing a jacket.
When Tom and Nola play chess, the amount of wine in Nola's glass changes between shots.
When Chris tells his friend about the affair, his right arm is up, then down, then up again between shots.
The computer screens on the detective's desk read 'London Police,' which does not exist. It should read Metropolitan Police, City of London Police, or British Transport Police.
In the Royal Opera House, the performance of "La Traviata" is, inexplicably, accompanied by piano rather than full orchestra. So is the later scene when Mary Hegarty sings "Caro nome" from Verdi's "Rigoletto."
When Chris goes to the police station to be questioned, Detective Banner hands him Nola's diary. The diary would be considered evidence. There is no way someone not working law enforcement would be allowed to handle it, especially a potential suspect.
When Chris shoots Nola and her neighbor with a shotgun, it is hard to believe that it would not have attracted considerable attention in a city with strict gun laws, especially considering the amount of time between the shots. The sound of a shotgun being fired is about 150-160 decibels, higher than the noise on an active aircraft carrier deck.
An ornate clock face is shown in closeup for several seconds, indicating a crucial time for the main character's murder scheme. The minute and hour hands on the clock are grossly out of sync with each other: the hour hand shows approximately 6:12, while the minute hand shows 44 minutes after the hour.
When talking outside the car with a friend he runs into, over half a dozen extras across the street walking on the sidewalk are looking at the two actors.
Nola calls Chris on his mobile when Alec and Eleanor Hewett are visiting. Chris's Motorola phone plays Nokia's default ringtone.
The police would discover Nola's pregnancy obviously. That would make Chris much more suspect, especially after they did DNA checks, which there is no way they would not do.
When Chris steps out of Cartier and returns to his car, he meets a friend who still plays the tennis circuit. As Chris steps around the rear of the car, the boom microphone is visible in the car's side window.
At around 0:35:00 when Chris and Mr. Hewett are in the gun shack at Hedley, Tom walks in late, and Mr. Hewett accidentally calls him Chris.