As rail guns use magnetic forces to propel their payload, they contain no propellant material unlike conventional weaponry, due to this no "fireball" will come out the end of the barrel during firing. You will only see a cloud of water vapor as the air condenses.
When searching through satellite imagery to find Gillian and Zoe, Darius has the tech bring up the last 24 hours. They are fast rewinding when Darius tells him to stop the feed. His reaction is slow, so they would be several minutes or hours away from where Darius wanted the feed to be, yet the girls are immediately in shot.
Zoe is ten weeks pregnant yet shows no reluctance to drinking a glass of wine at the COPE compound.