When there were two refs, I knew each of their responsibilities. Now with three refs, I am unsure what the responsibilities are for each position.
But as the three refs rotate, they each shift responsibilities and they each have their own nuances and they each see things slightly different. Then you factor in their egos, the speed of the game/players and the size of the players.
Contact should be a foul. That is what the rule book says. But hey, let's tweak the rule book and yet not change the rule. We will simply judge whether or not the contact actually impedes the player, and oh yeah, it different if it is big on big, or small on small, and is completely different if it is small on big. Traveling, oh yeah, I remember when it was a violation. We will only call 3 seconds a couple times a year, we need to let fans know we can count...lol.
I keep hearing how difficult refereeing is, hmm. Adherence to the rules is hard. Thank gawd police don't have that issue, right?
If it is too hard for humans, computerize it. It can be done.