Continuity mistake: In the scene in the National Gallery early on in the film where Bond meets Q, there is a line of bench seats they're sitting on. From behind, Bond's coat tail is barely covering the gap between two of the benches. From the front, though, his coat tail is further back, covering the gap almost entirely. (00:37:05)
Continuity mistake: When Silva is first seen in the London Underground station, he walks down a flight of stairs. On the left side of the stairs, there are two men. In the next shot, it is now only one, an entirely different man. (01:28:00)
Continuity mistake: After Silva shoots Severine, he never puts his gun down. As Bond begins shooting the henchmen, Silva can briefly be seen, gun in hand, running backwards away from Bond. When Bond kills the last of the henchmen, and turns to Silva, Silva is unarmed.
Answer: Silva's objective was not just to kill M - if it was, he could have blown up her office with her in it when he hacked into MI6 the first time. He wanted to humiliate and terrify her by showing he could get to her again and again, whatever measures were put in place to protect her.
Sierra1 ★