It's only a 1.7 made field goal difference from being 31% shooting. As if 4.7 out of 15 attempted field goals is drastically different to 3 out of 15 attempted field goals. The point is, they both were horribly inefficient FG-shooting wise and the Cavs not only were still in the game, but actually won it and you're out here saying the Cavs wouldn't even be in the game if LeBron shot the same from the field. I imagine you'd find other instances of his shot being off (during multiple periods) and the Cavs were still in the game during low-scoring contests.
He also had a 4-13 performance against Memphis last season and the Cavs not only were in the game, but they won it by 30 points. There's your rebuttal right there.