NCAA Rules - PAT after a score when time expires.

[JasonTX]

From the rule book:

2. A try is an opportunity for either team to score one or two
points while the game clock is stopped and is a special interval in a game
which, for purposes of penalty enforcement only, includes both a down and
the “ready’’ period that precedes it.

a. The ball shall be put in play by the team that scored a six-point
touchdown. If a touchdown is scored during a down in which time in the
fourth period expires, the try shall not be attempted unless the point(s)
would affect the outcome of the game.

I think the key part in bold above "oppurtunity for either team" seems to indicate that both teams are entitled to points so if the game could be decided by a 2 pt. return I think the try must be conducted.. By saying the game is over after the TD and not requiring the try you are taking away the "oppurtunity" that team B is provided in the rules and those points would affect the outcome of the game.