At the end when Amanda is looking at surveillance pictures of Nikita and Michael's engagement dinner, Alex's arm sling is nowhere to be seen. In the opening, when they were showing them at the dinner, and where the pic was supposed to had been taken, she had it on.
Nikita uses a machine gun to create a perforated arc in a wall in order to punch out a section/hole to get through, however when she does get through, the broken piece of wall that falls away is inside the machine gun perforation holes and not along them.
The car that Amanda is driving has an invalid German license plate.
At the end, it shows that Amanda and Ari are hiding in Antwerp. But in fact, the area shot is from Ghent, another Belgian city.