Jeez dude, the first promise with a follow-up j/k was fine, but when she asks again, maybe put some thought into asking some clarifying questions before making such an open ended promise and end up agreeing to take on a whole country or something.
I get the feeling Hiro was getting involved regardless of the promise/offer he made. Why? Because legally, he's got her for 7 days. I don't think the villain will wait that long.