Salman Khan's hairstyle keeps changing throughout the film as it was in making for 3 years, In many scenes he has long hair of Saajan Days while in some scenes he has the short hair he had during HAHK days
In the climax when Aamir tells Crime master Gogo more about his childhood expression, Gogo in a long shot holding a gun on his right hand happily shouts to everyone about what others were thinking about him. A close-up is followed afterwards and it is visibly clear that Gogo is holding the same gun on his left hand without revealing why and how.
When Robert accidentally strikes Bhalla with an "iron bar", you can clearly see it bend on impact.
In the scene where Anand Akela shows Prem his token for the interview, Prem places it on the table. All three characters are shown to move away at the end of the scene, but Anand doesn't pick his token back. He reveals much later that he has given up hope of marriage to Raveena, but its only after their attempt to foil the plans of other hopefuls.
During the scene where Salman and Aamir meet in the lodge, after Aamir gets released from jail, Aamir asks Salman how he is. Salman replies "Tip Top" but the visual looks like he doesn't say anything at all.
If Amirali Aslilali Asli (Salman Khan as an old Muslim Miyaan or gentleman) has his fake outfit busted and gets beaten up by Robert, Bhalla and everyone else, how is that same person able to come back to the Bajaj house as Dr. Prem Khurana? They would have obviously recognized him.
If Raveena Bajaj was so famous in London, the press folks in London and Bombay would have easily known when she switched identities with Karishma Harishankar after landing in India. In those days, there was no Internet, cellphones or social media but film journalists and news folks were everywhere. It wouldn't have been possible in 1994 that no one knew what Raveena Bajaj looked like in her earlier life in London.