At 1:23:42, towards the end of the film, a boom microphone can be seen: as Emily leaves the bathroom and collapses, the boom appears from the right beneath the archway and then pulls back out of view.
At 7:29 they are discussing the comet and Lee refers to the "Haleys" comet, a common mispronunciation. It should be Halley’s Comet. While such a slip could be plausible for an inexperienced speaker, the fact that much of the dialogue is improvised indicates it was an error by the performer.
The actor is a real person portraying a fictional character and so is liable to the same quirks as the person they are representing at that moment. Anyone who grew up in the years after the first wave of rock 'n' roll (the 1960s and 1970s) will be familiar with Bill Haley and His Comets (best known for "Rock Around the Clock"). That popular association led many to believe the comet was named after someone called Haley rather than Halley. People who learned the incorrect version passed it on to their children, friends and acquaintances. As a result, someone raised with the misnomer — even if they later corrected themselves — may still unconsciously use the wrong pronunciation, especially when drinking alcohol.
(at around 29 minutes) Lee places a plaster over the scratch on Hugh's eyebrow. A moment later, while they are discussing a photograph of Amir, the plaster is gone. In the following shot the plaster reappears.
Shortly before 1:22:00, Emily is wearing a coat she took from another Emily in her car. Then, whilst her friends are watching the comet, she is suddenly without the coat, particularly when she notices another Emily crawling into the bathroom.
(at around seven minutes) Immediately after Hugh asks everyone at the table about their phone signal, but before he begins discussing the comet from the 1930s, there is a brief shot of Lee speaking. A cameraman can be seen crouched behind the sofa in the lounge, to the left of Lee's head.
In the closing credits, the name of singer-songwriter Laura Veirs is misspelt as "Laura Viers".
(at around 1h 6mins) While Hugh is working out the different outcomes on his iPhone, the screen clearly shows he has signal — which the others insist none of them have.
