Theory to explain that Al Gough states that Rutherford is 25 years old, contradicting the age that would be suggested by the birthdate in his passport is that 2 years were spent outside of his normal timeline making him 25 after only 23 normal years within the timeline. Alternately he could have come through in the FlashForward from another earth that is out of sync with the one in the series. Either fits the shows' current 'bible' (as in what's been shown so far).