Lots of people probably turned down Steve Jobs for similar reasons and now have similar regrets. It can be hard to tell the difference between a skilled hustler and a bullshit artist. Perhaps the only real difference is what they choose to sell.
Faced with a similar dilemma I would ignore much of what the hustler was telling me and talk to the other people involved (i.e. the technical co-founders) and try and base much of my impression and decision on them and how much trust they have in the hustler. Since they've done so well I have a feeling if you had done this you would have gotten something like 'ya ya he's a bit over the top but he's a really smart guy and we are doing great things here' etc. This may have led you to making a different decision.
Faced with a similar dilemma I would ignore much of what the hustler was telling me and talk to the other people involved (i.e. the technical co-founders) and try and base much of my impression and decision on them and how much trust they have in the hustler. Since they've done so well I have a feeling if you had done this you would have gotten something like 'ya ya he's a bit over the top but he's a really smart guy and we are doing great things here' etc. This may have led you to making a different decision.