Let's posit for a moment that all pre-match conditions had been satisfied. Butterbean accepts the deal with the understanding that he will beat Bart in the match, and Bart agrees to these terms. Perhaps they even accept a legitimate fight with the understanding that Bart will take the fall. Whatever the case, the match goes forward as we first witnessed.
At some point in the match, perhaps after Bart has already sustained a few critical blows, he fires up for a comeback sequence that will quickly escalate into Butterbean's victory finish. However, due to in-match circumstances (fatigue, blurred vision, lost balance), Bart attempts a desperate wild swing (think Hansen's lariat), and it connects. Butterbean collapses, and the referee is left with no other choice but to declare Bart the victor after Butterbean is unable to respond. Maybe this scenario would find more acceptance among the armchair quarterbacks.
Regardless, say Bart wins. What next? I can see the likelihood of management forcing him into additional Brawl-for-All or similarly stipulated "tough man real fight" contests, though the steam would have probably run out shortly after Wrestlemania. General fans, myself included, were not taken in by the Brawl-for-All concept, and its passing was met with silent apathy. Few were sad to see it go.
A more likely scenario might have involved a brief win streak and even a short Euro/IC title run for Bart before he got decisively trounced by a rising superstar. Since his win in this proposal was unexpected, management would probably want to reap some sort of business from that before shuffling Bart to the back of the deck.
