Duff, I don't think police dispatch radio is what the original article was talking about with regard to encryption. It seemed to be about tactical radios used by the FBI, etc.
If the rekeying protocol is performed over the air, how does rekeying help in your corrupt cop/gang leader scenario? Wouldn't the gang leader's radio get the new keys along with all the other radios?
I agree. I don't know who this guy is, but if the superior holier-than-thou attitude that drips through that blog post is any indication, I'm surprised that anyone would ever ask him to speak. At least not twice.