You can die by a firebase after the game has ended. Just like an airstrike. It's pretty annoying to see you helplessly get shot a hundred times and then watching yourself die... I don't think there are other ways but it can get pretty lame.
Same if they build a turret late and its in progress of building when the game ends. I've been killed many times this way by lvl 1 rock-it turrets.... Edit: also sniper flaks
This is really annoying, especially for people trying to take down the ball who have airstrikes spammed at them in the last second. Also, when someone gets a kill after the round ends their money won't total up correctly. I notice that when we win and I get an after round kill (or get killed after the round) I am usually ~50$ off from the correct amount.