Wizard's Life-Debt (was PoA question and Sirius)

[baringer2k at aol.com]

No: HPFGUIDX 50394

Perhaps in the Wizarding World an order received by a familiar (a cat, owl, or otherwise) would not be so strange.

What I'm wondering about regarding PoA (and which impacts future books) is what Harry was told at the end when he allowed Wormtail to live. He was told that a life-debt is something a wizard never forgets, and is bound to. Considering how much Rowling loves to give us astounding attention to detail, I'm sure that will come up.  I think that, if the situation was darker for Harry at the end of GoF (COULD it have gotten ANY darker??) that Wormtail's obligation would have made itself known. But to what extent must Harry be in danger for that debt to come into play?