The bet, and the basis for the newspaper story that was supposed to be the outcome after the two-week bet, was to prove or disprove the newsman theory that a man with NO gun skills can survive by bluffing his way, based on his reputation and the way he carried himself.
As soon as the kid lined up those bottles on Front Street and shot at them, the bet should have been called off. First, the kid missed one out of five, and did not shoot each one using a fast draw. That in itself showed that he is not up to par with most gunslinger, and would increase the chances of some punk seeing a chance to win if they called him out. Second, even if his display of skills had been impeccable enough to discourage challengers, that would not serve to prove or disprove the theory of an unskilled man being able to survive by BUFFING alone. Either way, the kid rendered the newspaper story moot, since the premise changed half-way through. If the bet had been called off due to the terms not being met, there would have been no reason to employ any shenanigans to get the kid murdered in order to win the bet.
I dropped the score a couple points for that reason. It just made no logical sense to me why the bet was allowed to continue after the kid quit basing his survival on bluffing, resorting instead on proving his skills (which were subpar).