Plot hole: When Bond climbs out of the lift he has been hanging onto underneath, how does he know the villain went right and to go that way? Yes, the lights come on automatically when someone walks past them, but Bond was climbing up and out of a lift. By the time he gets to the hall, all the lights are out.
Plot hole: Silva spent years planning his revenge against M, yet the ability to carry out his plan depended on conditions that were entirely out of his control, such as being captured by MI-6 despite having no way of knowing that Bond was coming for him, and only escaping custody because Q triggers the trojan - there's no way Silva could predict when that would happen, could have been hours, days, weeks, or never. He then ambushes M at the court house despite having no way of knowing that she would be there that day.