In Laurent's first scene (and only that scene), he (and no one else) pronounces Duman's name as "Dumain".
When Duman's men come out of the house to confront a yelling Claude Laurent, they are seen screwing silencers onto their handguns. When Michael gets Laurent into the vehicle and start to drive away, the guards fire several shots that are not silenced.
Madeline says the stereo was wired into the ignition and now the car won't start. It is impossible to wire any device into the ignition system of a car, let alone have the device disable the car when it is removed. It is more likely an ignition wire was inadvertently cut when the stereo was removed.
When the fake Gustavo goes over the railing, it's obviously a dummy.
When Westen and Laurent flee Duman's house on Star Island, we see a street sign for S[outh] NORTHLAKE DR[ive]. The only street on Star Island is Star Island Drive.
When talking about his family, Jean Pierre Duman says "We left the Island of Haiti". Haiti is not an island. The island Haiti shares with the Dominican Republic is called Hispanola.
Jean Pierre Duman mispronounces his alias Luc as Luke. As a french speaker he should pronounce it with a short y sound for the u and a cut of k sound for the c: "Lyk"