in the first half of every game, regardless of the circumstances. He's been doing that for years. Once when Mario Austin had maybe 10 points in the first 5 minutes, out he came for Marcus Campbell at the 15:00 mark - it was in the game script.
The second half is a different situation. Quite frankly, I was amazed that he subbed at all in the second half tonight. Ususally this year the starters have to handle the entire second half, as well as any overtimes.