One thing I hear on my TeeVee from the punditry class of aviation experts regarding this mishap is that the military and civilians aren't on the same freq (UHF/VHF).  They speak as though mil helos can't monitor/talk on VHF.  Is this an anachronism (mil only talks on Uniform)?  Are there any mil helos that can't dial up a VHF freq?  Whether or not they choose to, or are required, is another story.