Why did he say that?
After the challengers correctly answered the Final Jeopardy question, they had $10,001 and $11,601. The champion had $13,200. She answered correctly. Alex said: Did she risk enough?
Alex - she couldn't lose if she got it right. There was no "enough". She was ahead with a ZERO wager. (Actually she wagered $8,000, of which Alex said, "That's enough!")
Maybe he was overcome by habit?