Not really a 'briefcase' though. If someone came into an office where I was with something that thick, I'd suspect they were carrying something other than a netbook in there. The back pack was a lot more stealthy, you know people carry stuff in them, not lightweight papers.
Not really nit-picking, it's at least 10-times less conspicuous than someone carrying a baseball bat bag around in an urban environment.
I don't know about some of these rifles, but I know for some of the other really expensive rifles that piece together from a case like this have some fairly sophisticated mechanisms to make sure they snap into a very tight and secure center. Without that, you're right, what good would the first shot be, or even follow up shots for that matter.