Audio problem: When Tony is about to kill Frank, Frank says "Look Tony, please don't kill me." You can see that he is not saying anything. His audio is obviously added in by Post Production.
Continuity mistake: In the scene where they are having dinner at the Babylon Club, the waiter brings them champagne and when they all raise their glasses to toast, Tony has a cigar in his mouth. The camera cuts away and then cuts back to Tony about to take a drink of champagne and the cigar is now gone. There was not enough time to take out the cigar. A second later the cigar is back. (00:37:10)
Revealing mistake: At the end of the infamous chainsaw scene Tony takes an automatic pistol away from one of the Colombians after a struggle in the shower. Tony pushes the Columbian away, extends the pistol and fires a round. You see the gun's hammer drop and the muzzle flashes, but the slide does not cycle, a clear sign that blanks were being used.
Continuity mistake: Tony Montana has a heart tattoo on his right hand between his thumb and index finger. The heart rotates 180° from when it's first seen to later in the movie. (00:05:45 - 01:41:50)
Revealing mistake: When Tony shoots Hector in the head, you can tell they stuck a red sticker to his head to simulate a bullet hole. You can tell this because there's a little bit sticking out, which is what they'd use to take it off.
Other mistake: When Tony pulls his arms down from the shower curtain, there are no chains on either of his arms, and at no time do you see them fall in front of him.
Other mistake: Manny is shot in the scene in the motel, but when he is in the bed with the naked lady, there is no sign of any type of bullet wound in his chest, side or arm.
Continuity mistake: When the Colombian is shot dead on the road, his position changes between shots.
Continuity mistake: In the scenes after Omar is killed in the helicopter, Sosa and Montana are talking business gangster style. Montana's body shifts positions all the time as the cam cuts, one time he is standing with his arms akimbo, next he is bringing his hands to his hips, and all the time his body's angle is shifting.
Continuity mistake: When Tony leaves the bathroom in the motel scene, the bathroom light is on and it is bright. When he leans over Manny, the bathroom is now dark.
Continuity mistake: In the motel chainsaw scene, before the Colombians pull out their guns, there are several food containers, a bag of cookies and a soda can lined up neatly on a table, seen in multiple shots. After the skirmish, Hector pulls the chainsaw out of its box and Tony is leaning against the table with the items now all scattered in different positions. A few minutes later, Manny shoots his way in. You can see the table in multiple shots and the items are back in their original positions.
Continuity mistake: When Tony shoots the narcotics detective, the detective's gun disappears from his holster shortly before he is shot.
Continuity mistake: When Tony's car returns after killing Manny, it enters the compound gate. Men are climbing the wall from the inside, leaving to the outside wall. Either the car is going the wrong way, or the assassins are. The gate opens away with the security camera facing the gate. So it appears Tony is leaving while men are entering. Maybe this scene was meant for when Tony left to find his sister? But it happens after. (02:29:08)
Visible crew/equipment: When they are leaving the Porsche showroom/garage, the entire crew is perfectly visible in Michelle Pfeiffer's sunglasses.
Continuity mistake: At the end of the film, Tony drops his M16 when he is shot over the barrier. But when he falls into the pool, his M16 has gone.
Plot hole: During the scene when Tony Montana is at the Babylon Club talking to Manny after he speaks with Mel Bernstein He says to Manny "Who else knew about that Rebenga Hit, Omar? He's fertilized." But what he failed to realize is that there was someone else who knew of the Rebenga Hit and he is the guy who was in the car with Omar during the first time they met while Tony and Manny were still dishwashers at the restaurant.
Audio problem: At Tony's interrogation at the Immigration Office, the voices of two of the INS Officers are shoddily dubbed over. This error is made even more noticeable by the fact that the first officer has been replaced by the distinct voice of actor Charles Durning. The other officer is voiced by Dennis Franz.
Continuity mistake: When Tony is supposed to do the assassination for Sosa they are following the man and his family in a car. There are two beer cans and chinese food containers on the dashboard. When it shows Tony and the rest of the people in the car one of the cans is smashed. When it shows the view of the car in front of them it isn't smashed. The can changes from shot to shot. (02:18:00)
Continuity mistake: Angel is killed in the tub in the motel, but his body is not in there when shots of the tub are seen. Also, if the body were still in there, Tony and the other man would not be able to stand or move back and forth as easily as they did as they would be slipping and stepping on body parts.
Continuity mistake: While Manny and Tony are working at the bar, before starting in the drug business, Tony has a towel over his right shoulder. Depending on the angle the towel covers part of his spine or it doesn't.
Answer: It's unlikely a set up. Tony is supplied with money and guns to defend himself. If this was a setup, the toad would've had more details. He would've known Tony had backup with guns and they would've waited to ambush them. Also makes no sense for Omar to put himself at risk without a legitimate opportunity to make cash. Frank knew about the deal as he supplied the buy money. Omar seemed loyal to Frank. Why would he send some low level thugs to be set up losing his boss' money in the process? All he would do is lose trust and be suspected.