Quite true. The lack of a media event probably has a negligible impact, although since UBS initially reported it, some investors my put some weight in that report, since, well, it's from UBS.
The whole France thing shouldn't impact the stock, but it will because it's "bad news". As you say, you can drive yourself crazy wondering why stocks go up and down. Take the price of oil right now - it's stil inflated. And then last month when those Shell employees were kidnapped, the price went up!
Yes, because 9 Shell employees got kidnapped, the price of oil therefore must rise $2/barrel.