Starman has it exactly right! Never seen it in 20+ years of working NCAA football in Europe but it could happen.

I think the most likely way for it to happen would be a series of penalties (a bunch of USC, most likely) would put the spot close to A's goal line, and then the result of the try's being a safety. Usually leading by a TD pending the try, team A in such a situation (and no longer being allowed to decline the try IIRC) would take a knee, but if it occurred early in a game that was expected to be high scoring they might try to score on the try and as a result give up a safety.

Robert