If I understand the article, he received notification of the probable impact area of a meteorite moving fast enough to suggest it probably did not originate wit

If I understand the article, he received notification of the probable impact area of a meteorite moving fast enough to suggest it probably did not originate within our solar system. Fair enough. But then his team didn't really find the impact site itself. They just drove a magnet sled around the area to see what it picked up. They found tiny spherules. Okay. That suggests something that was melting in the air. But couldn't that have been from any of a thousand other meteorites? Couldn't it have been volcanic? Couldn't it have been ancient, rather than modern? Did he also drive his magnet sled in other areas that are not in the impact zone of that meteorite? What did he find? This seems to be a lot of wishful thinking.