Definite knowledge?

[RookieDude]

I was watching a game the other night. Two veteran officials. Ref 1 counted a Three pointer during the game. Later in the game, Ref 1 told the home book keeper he didn't think it was really a 3 point shot. Ref 1 said he made a mistake in counting it. (It counted for the visiting team.) The home book keeper sort of shook her head like, "no it wasn't a 3 pointer". Ref 1 said "take away a point, I have definite knowledge now that it was not a three." Ref 2 said, "You're going to take away a point now?" {this was all happening during the break between quarters at the scorers table}...Ref 1 said "yeah, I believe I got it wrong." Ref 2 was the Referee for the game but he told Ref 1 he was going to have to tell the Coaches what he was doing...i.e. taking a point away from the Visiting Team. Ref 2 said "sure, no problem." Well, as you can imagine the Visiting Coach was upset that he had just lost a point. At the time it was a 3 point game, now a 2 point game. This was during the 1st half. Visiting team ended up losing a close game by 6 points.
What are your thoughts on this? I know it says in the Rule book a Referee can change the score anytime during the game if he has definite knowledge...but I thought it was more for if the Scorer had missed a signal or something.