It's not a question of a "fix," but of refs predisposed to a certain outcome looking more closely at one team than the other, and calling ticky-tack fouls that change the outcome of the game. The Hawks are the new kids on the block as far as post-season play is concerned, so the refs are more likely to think they don't belong, and more likely to throw flags against them.
Like the NBA travelling calls. If you were Michael Jordan you could run all the way down the court with the ball. If you were a rookie all you had to do was flinch.
Let us ask this question, Would a ref be more likely to make a call the wrong way out of favoritism that could cost him his job or out of economic incentive?