13 outs if you call the all-in with the aim of drawing to the straight or the flush. 9 diamonds, 3 2's that aren't a diamond and the 3 7's that aren't a diamond. I didn't crunch the exact numbers but Hansen would have less than a 50/50 chance considering that if another 3 comes, an ace comes, or the board pairs on the turn or river then Hansen would have to catch the straight flush to win the hand. This is not a situation you want to put yourself in when you would still have a nice stack if you folded. In my opinion it would be wiser to save your chips for a situation where the odds are more in your favor.

I think you have Hansen and Lederer mixed up Humpy... From what I've seen Lederer is a fairly tight player and Gus is quite the opposite. Hansen is loose in the sense that he will call pre-flop with hands that a lot of people wouldn't consider playing. Because his play on the flop is so damn good as is his ability to read people he can get away with it though.