I doubt that one conference decided to let them take their heads off and another said lets be real ticky tack and throw people out of the game for nothing.
There are bad refs everywhere. With rules like this that can take some judgement, unfortunately you will see calls that are not consistent.
I'd agree that it's no conspiracy, yet the outcome couldn't be communicated much better than you describe. One call borders on ticky tack while the other is not called even though flagrant.