School dress code-- male w/ curly hair...?

My 16 year old son has been home-schooled for 4 years and is now returning to public school. Dress code for the school states that boys' hair can be be no longer than the eyebrows in front, must be above the bottom of the ears, and can not touch the back of the shirt collar. We abided by these guidelines when we took him for a haircut prior to the first day of school. My son has naturally curly hair-- keep this in mind , please.

On the 3rd day of school, I was called to come up to the school. The vice-principal informed me that my son's hair is too long, because when the curl is manually pulled down and stretched out, it is longer than the handbook/ dress code guidelines. The VP stated that we must cut his hair, as other long-haired boys have tried to get by the policy by brushing their bangs aside or tucking it behind their ears and arguing that it was above earlobes, not below eyebrows, yada yada yada. My arguement on that is that those boys are manually manipulating their hair to duck the policy--- my son's hair, in its natural fall, NOT being brushed aside, tucked behind ears, or having the dang curls pulled out straight, is within the dress code guidelines according to the handbook. Nowhere does it state anything about when the hair's natural state of being is manually manipulated how it is to be measured.

We aren't refusing to cut his hair, it isn't long, and there is no religious or cultural issues about the length of it. We just find it somewhat discriminatory in regards to him having naturally curly hair and the fact that they are measuring it by having him pull the curls straight to determine how short it should be. And before anyone can ask-- no African Americans with 'fros in the school, so I can't argue with them about making the VP stretch their natural curls out to define length...lol

We did get him another haircut-- and it is absurd looking as it is only about 1inch in length in front-- as it is VERY curly, and after cutting it to his eyebrows while holding it straight, it sprung right up. I am intent on refusing to cut it again once it grows back out, so long as it is within policy in its NATURAL CURLY STATE. I am just looking to see if anyone else has had this situation with their child, or themselves, or can site some references to similar issues they may know of. Thanks!!