Look, it really is THIS simple. Games are OFTEN close in the NBA, when they are close, it comes down to a couple things, concentration, execution, sometimes merely the bounce of the ball. What you DON'T need on top of those things is the distraction of having to overcome mistakes? (is it even possible that 3 highly trained professionals ALL missed the fact that his foot was in the circle, when that's freaking what they look for?) made by the refs. That blown call was a 5 point swing.
That's all you need to overcome a 4 or 6 point lead.