I am pretty sure it wouldn't take the GE 15 minutes to calculate only your game (I mean it has the rest of your country + teams that are in similar time zones to yours). Probably only a matter of seconds to a minute so it doesn't surprise me that you can view all of the information during the 15 minute Cut-off period.
And i am not saying that during the time when you are "Watching it Live" it hasn't been determined just stating that i would assume the point of the GE is to work out the final score of the teams + all of the events that would happen (from passing the ball to a player getting injured).
And i agree with you about why they don't allow you to change after the lock-out. I mean what programmer in their right mind would want a user to change the variables that the GE is using while it is processing the results (And i am talking about in this particular instance not programs in general lol)
Neeber
When the Beasts Roar all in the way shall be struck down!!!!!