"the abuse of" = "the waving of". It is the principal who abused the flag. These kids brought honor unto the flag.
When shoved into anyone's face, it is abuse, not only of the flag, but of the unfortunate victim. No one who treats the American flag with anything other than respect brings it honor. As I said before, they abused the flag and got what they deserved. What they truly need however, is for someone to sit them down and explain the proper respect and etiquette to be shown the flag. Apparently there are some here on FR unable to do that.