Not really; a moonshot is a huge investment to advance the state of the art in something where we know it's possible. It's not a wild shot in the dark.
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.