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 Tony's mom's house, as Gina is following Tony outside, from inside the house the window shade is halfway down, but from the outside it is all the way up.
Continuity mistake: During the shot of Freedom Town there is a resident in a distinctive brown patterned shirt that keeps passing by in the background of the shot with Tony. When Rebinga enters the camp the same person in the brown shirt is entering the camp with Rebinga, only with a pronounced limp.
Continuity mistake: When Shadow is shot, in one shot he's touching his face, but in the very next shot he's touching the detonator on his lap.
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.
Omar was an informant. He wasn't loyal to anyone. Omar's driver is the one that suggested to send Tony to the Colombians. And I think Omar knew the Colombians were shady, and that's why he sent Tony. It was, in a sense, a setup.