It doesn't have to be GA; you get the same result in piwik. "No keyword" is always at the top of my list. Same thing in your raw logs. At best it's "q=" and then jumps straight to "cd=somenumber". (Oh, how nice, I came in at the top of someone's search. Now if only I had some clue what they searched for ...) At worst it simply shows up with google dot com as referer with no hint that there was even a search involved.
Q: How does this work in wmt? Look at searches and pages and there's no hint of missing search terms.