I'm going to chime in on this with a couple of things I saw in the CBHS-McCallie game. #28 for CBHS should have been kicked out of the game, or at the least penalized more than once for unsportsmanlike conduct. While he was on the crease (offense), he attempted to hit #2 for McCallie in the family jewels with the end of his stick, multiple times. He was called for this, and as soon as he got back on the field, he did the same thing again, this time to #7 for McCallie. Ball went down near them, and instead of going for the ball, he went right at #7, hitting him repeatedly across the chest (not a cross check, but close). #7 pushed back once, and then dropped it, but #28 kept trying to start a fight. I know there was an exchange of words, but that outbreak was still uncalled for. No flag thrown at this either, although it went on for ~5 seconds. The final thing I saw #28 do that was dirty, and just plain stupid, was KICK #9 in the chest while Penn (#9) was on the ground. It was in the open, and everyone saw it, and there was no flag thrown. It wasn't an accident either, as Penn's body moved about a foot when the guy kicked him.
In our (McCallie) game against MUS, they (and us, for the most part) played a fairly clean game, but there was still a clear bias against us. The ref bias in the CBHS game was much more evident, and I'm going to say that it is not a stretch at all that the refs were extremely biased towards CBHS, especially since it is such a heated rivalry.