For a game based on time I'm surprised time continues even AFTER you've finished. That should be a simple fix, simply lock your time in place and then calculate time of computers after.
Not sure if anyone else encountered this but it keeps happening to me...when you press pause the game gets all wierd and will only move when you either shoot or hold down the mouse on the play button. However, you can reload while its frozen...makes no sense. I is confused.