It seems you can get upvoted for no apparent reason :)
As far, as I can verify, it was me who made the upvote. Out of fun and out of curiosity. I also thought it was inconsequential since the answer will get flagged and removed soon and since I would remove the upvote few minutes later anyway. I didn't care that the answer was just posted, nor did I know that there is a badge for upvotes.
I can't answer the general question, I would just suggest that there is a plethora of disconnected reasons why a gibberish answer may get a single upvote. In statistical terminology these would be considered measurement noise. To continue the analogy I suggest we avoid overfitting by closing this question :)