Plot hole: When the Security chief is discussing the plan with the assassin, they are overheard by Nicole Kidman over the General Assembly microphones through a pair of headsets. Normally all this equipment is turned off when not in use to protect the system. The sound man had time to turn it off before he left even with an evacuation in progress. There was no way that the two were intending to be overheard either, as there was no way that either of them knew if, or when, anyone would be in the booth.
Character mistake: In the beginning of the movie, Simon Broome and Xola speak in English and Xola acts as the only speaker of Ku. He confirms to Simon that the three young boys are Ku but if Simon grew up as a Matoban like Silvie, he would have been fluent in Ku as well.
Chosen answer: At this point, she has set her mind on killing the African leader and knows she'll likely be killed immediately afterwards (police, bodyguards, etc). She's writing her name in anticipation of her death.