When Devika is leaving Aarush with her boyfriend on the beach, his tie is suspending straight downwards, but in the very next shot, it is swinging to the right. In the next shot, it is again downwards.
In the Buckingham palace scene, the people are shown smelling the nitrous oxide and starting to laugh. In reality, nitrous oxide AKA laughing gas is odorless.
Arjun Rampal's characters tell Akshay that he cannot fool a lie detector. This isn't true as lie detectors are never 100% accurate and often give incorrect or inconclusive results.
Lie detectors do not look like the one shown in this movie. They certainly don't have a "True" and "False" light which light up based on the answer of the person being tested.
Despite being set in London at the end of the movie a truck with registration of Karnataka India is seen.