Game 3's free throw line reversal was real shocking

As any gambler will tell you, if you have information about how many times a randomly occuring event has occured in a sufficient number of past opportunities, you should be able to confidently predict the percentage of times it will probably occur again in the future by stating it as a percentage of future opportunities (eg over the course of any baseball season, 21% of all batted balls will be line drives). But when it comes to predicting the number of free throw attempts (random occurences) an NBA team recieves as a percentage of the 2 point field goal attempts (opportunities for the occurence) it takes, you cannot do it.

Somehow that ratio, which logic says ought to be constant, fluctuates wildly from game to game. For instance, in Game 2 of this series, the Celtics free throw attempts to 2 point attempts was above 70%, and the Lakers was in the low teens. Then last night, we move to Los Angeles, and the Celtics ratio drops to 33.8% and the Lakers skyrockets to 61.8%. The only logical explanation is referee bias, and it really should stop. A foul ought to be construed as a foul regardless where its committed. The way the referees control the game is really starting to annoy me, and its opening the game up to dangerous allegations about its legitimacy.