In several car chase shots, the car gets hit or has parts destroyed and in the next scene, the car is like new.
When Bohra (Danny Denzongpa) inserts the Red-Chip into Chitti (Rajnikanth), he says "Panam yenakku, pazhi DOCTOR Vaseegaranukku". However, when Chitti replays this footage in the court towards the climax, Bohra (in the video) says "Panam yenakku, pazhi ANTHA Vaseegaranukku"
When asked the robot replies that there are a finite number of primes of the order of 4 billion, however it has been known since the Ancient Greeks that there are an infinite number of primes.
After the initial demonstration and charging, when Dr Vaseegaran transfers data (before Aishwarya drops at the Lab) the monitor shows "Nueral Schema" instead of "Neural Schema" - a spelling mistake in "Neural".
It seems Danny Denzongpa delivered all the dialogs in Hindi. The Tamil dialogs were dubbed on top (with lip movement in Hindi)
During the song sequence of Kadhal Anukkal, the light reflectors and the crew are visible through the reflections that come from Rajini's sun glasses in many shots, especially in the shot at the beginning of the song where Rajini sits with the guitar in his hand.