What is the reason why the commentator said that?
He's talking about what Daniel is thinking. He's saying that Daniel is pretty sure that his pair of 2's is the best hand, unless Laak is holding a 9, which he could be (from Daniel's perspective).

So he's not saying that Laak needs another 9 on the river to win; he's saying that IF Laak were holding a 9, then he would be winning after that 9 on the turn.