Three men lost their lives in a fire in a capsule.

Well if we're nitpicking, that was the payload, not the Saturn V booster...

But unfortunate though that was, it didn't represent a fundamental uncertainty in the achievability of the goal - simply a fatal engineering mistake, which was immediately rectified.

The point is, how do you know your path is to the Saturn V and not the Soviet N-1? In the case of Google Moonshots, nobody even know if they're going to use a rocket.

I'm sure the N-1 would have worked as well, if the project had been funded (in both time and money) properly. The Soviet failure to reach the moon was a project management failure, rather than the failure of a blind risk to pay off.