There is a bit of misinformation here.
Fremont Trains are leaving Downtown Berkeley at 10:08 for every 20 mintues, 10:28, 10:48, 11:08, 11:28, 11:48, 12:08am, and then 12:30am. You have to transfer to a Dublin/Pleasanton train, but you can't transfer to the Dublin train anywhere, it's coming from San Francisco, and transfers are only possible at Lake Merritt, Fruitvale, Coliseum, San Leandro, and Bay Fair.
EDIT: ColoradoBear1 points out below that if you wait until the 12:30am train at Berkeley, you MUST transfer at Bay Fair.
It looks like the wait after get off the Richmond-Fremont train for the Dublin train is 14 minutes.
That being said, my experience with BART at Cal games is that the schedule is off right after the game. BART runs longer trains, waits for them to fill up at Downtown Berkeley, so I would think the schedule would be off. But there should be trains AT LEAST every 20 minutes at Downtown Berkeley going to Fremont, and longer trains for awhile after the game.
BART quick planner here:
http://www.bart.gov/Enter Departing station (Downtown Berkeley) and Destination (Dublin/Pleasanton) and date and time.