When Sudha and Tanu wake up from marijuana intoxication and are discussing about previous night, a mic is clearly visible in the bottom of the screen for about 15 seconds.
During the card game, Sanjeev Kumar reveals that he knew his father's name because after the shipwreck, he was awake and informed his manager about his and deven vermas name. If Utpal Datt (their father) was awake, why didn't he tell them that they had twin brothers as well? This would have led him to search for his and Deven Verma's twins and possibly clarify the confusion in the movie.