The army military uniforms are not being worn correctly such as the sergeant not wearing his chevrons on both sleeves and the general's collar "US" insignia in some scenes switches between the enlisted and officers versions.
In a close up shot, the briefcase Melvin Byrd is carrying gets shot, with the bullet hole dotting the "I" in "Melvin". In the next shot, the briefcase is merely dented.
When Melvin flies to the top of the hotel and switches "Diplomat" to "Mad Plot", the neon letters don't match the shot of the actual location hotel name.
As Melvin begins to fly after handing the tire he was holding to the cab driver, you can see a shadow of the flying rigging across his face and shoulders.
During the end sequence, at multiple times, you can see the wires and harness.