I just don't think the computer code logs minutes played by quarter or by game score or by last second shot taking.
I think the experience log works like this:
player date minutes played game type
Basketball Jones 6/11/10 46 PO
Basketball Jones 6/08/10 12 SC
Basketball Jones 6/07/10 22 NT
Basketball Jones 6/05/10 33 RS
Something like that. There very well might be some advanced intricate formulas, but I don't think so. The game types would relate to a modifier (SC and RS= 1, NT= 1.1, PO and CU =1.2 or something like that) that would adjust the total minutes played towards some amount (which seems to be between 1400 and 1900 minutes) which increases the player's experience.
That's how I see it working.
Once I scored a basket that still makes me laugh.