I'm a big fan of trying to imagine reasonable possibilities and giving both sides of any story I hear the benefit of the doubt.

But, in this case it's hard for me to think this is a mistake when the Navy's own argument is that it was intentional because they feel they had the right. A mistake like that may actually be defensible in court, and there would likely even be logs on the Navy-public server, not to mention logs of the communication that spread some kind of internal viral download -- half a million installs don't just happen without people talking.