This rock hit in a remote area with no people around. It could have just as easily have hit in the heart of New York, Moscow or London. There but for the grace of God...
Note at -50 when Yeomans pauses before he can remember that it was the second world war. He almost said World War 5, which proves he's part of the elite community that participates in the massive cover-ups every time there is an alien or undead world war. Most likely he's not even a real scientist but some salesman who got bought by the Agency after his drug or porn addiction ruined his career and family life.